FILED PURSUANT TO RULE 424(b)(2)
REGISTRATION NO. 333-159093


               PROSPECTUS SUPPLEMENT DATED MARCH 3,2010
                   TO PROSPECTUS DATED MAY 8,2009

This prospectus is not an offer to sell these securities and it is not
soliciting an offer to buy these securities in any state where the offer
or sale is not permitted.


                      RESEARCH FRONTIERS INCORPORATED

                       588,602 Shares of Common Stock

       117,719 Warrants to Purchase Common Stock at $5.00 per Share

                               -------------------


                           -------------------


Research Frontiers Incorporated is selling to accredited investors a total of
588,602 shares of common stock and warrants expiring February 28, 2015
to purchase 117,719 shares of common stock at an exercise price of $5.00
per share.  This offering is part of a "shelf" registration statement that
we have filed with the Securities and Exchange Commission which was declared
effective by the SEC on May 28, 2009.The shelf registration statement covers
the issuance of up to 3,000,000 shares of common stock, and/or warrants to
purchase such common stock. Each time that we sell our securities under the
registration statement, we will issue a prospectus supplement like this one,
which includes the terms of the offering such as the price, terms and amount
of securities being sold. We may sell these securities to or through
underwriters and also to other purchasers or through agents. We will set
forth the names of any underwriters or agents in the accompanying
prospectus supplement.

    Our common stock is listed on the Nasdaq Capital Market under the
symbol "REFR." The last reported sale price of our common stock on the
Nasdaq Capital Market on March 2, 2010 was $3.00.

                               -------------------

     Investing in our common stock involves a high degree of risk. See "Risk
Factors" beginning on page 3.

                               -------------------

     Neither the Securities and Exchange Commission nor any State Securities
Commission has approved or disapproved of these securities or determined if this
prospectus is truthful or complete. Any representation to the contrary is a
criminal offense.

                               -------------------

                              Per Unit(1)         Total Offering
Public Offering Price:             $2.75           $1,618,653.00
Proceeds, before expenses, to us:  $2.75           $1,618,653.00

(1) Each Unit consists of one share and one-fifth of a warrant expiring
    February 28, 2010 to purchase common stock at an exercise price of
    $5.00 per share.

Delivery of the shares of common stock and warrants to the purchasers
is expected to be made on or about March 3, 2010.


   The date of this prospectus supplement is March 3,2010



                  ABOUT THIS PROSPECTUS SUPPLEMENT

This prospectus supplement and the accompanying base prospectus dated
May 8, 2009 are part of a "shelf" registration statement that we
have filed with the Securities and Exchange Commission, or SEC. Each time
we sell securities under the accompanying base prospectus we will
provide a prospectus supplement that will contain specific information
about the terms of that offering, including the price, the amount of
common stock being offered and the plan of distribution. The shelf
registration was declared effective by the SEC on May 28, 2009.
This prospectus supplement describes the specific details regarding
this offering, including the price, the amount of common stock being
offered, the risks of investing in our common stock and the plan
of distribution. The accompanying base prospectus provides general
information about us, some of which, such as the section entitled
"Plan of Distribution," may not apply to this offering.

If information in this prospectus supplement is inconsistent with
the accompanying base prospectus or the information incorporated
by reference, you should rely on this prospectus supplement. You
should read both this prospectus supplement and the accompanying
base prospectus together with the additional information about
Research Frontiers Incorporated to which we refer you in the
section of this prospectus supplement entitled "Available Information."


                              SUMMARY

         You should read the entire prospectus, including the section entitled
'Risk Factors,' carefully before making an investment decision.

                            THE COMPANY

     Research Frontiers Incorporated ("Research Frontiers" or the
"Company") develops and licenses its suspended particle technology for
controlling the amount of light passing through a device. Such
suspended particle devices are often referred to as "SPDs," "light
valves," or "SPD-Smart " products.

     SPDs use microscopic light-absorbing particles that are either in
a liquid suspension or a film. The microscopic particles align when an
electrical voltage is applied.  This permits light to pass through the
device, and allows the amount of light to be controlled. Our offices
are located at: 240 Crossways Park Drive, Woodbury, NY 11797
(telephone: 516-364-1902).

                            THE OFFERING

Common Stock issued by Research Frontiers:     588,602 shares
Common Stock Outstanding after this offering:  17,111,329 shares
Warrants exercisable at $5.00 per share:       117,719 warrants
Use of Proceeeds:                              general corporate purposes
Nasdaq Capital Market Symbol:                  REFR

The number of shares of common stock outstanding after this offering is
based upon 16,522,727 shares outstanding as of March 2, 2010. It
excludes outstanding options and warrants (not including the
warrants issued in this offering) to purchase 2,486,841
shares of common stock, and options or other equity awards for
234,438 shares available for future issuance pursuant to the
Company's 2008 Equity Incentive Plan.

                           RISK FACTORS

         In addition to the other information in this prospectus, you should
carefully consider the following factors in evaluating us and our business
before purchasing the shares of common stock offered hereby. This prospectus
contains, in addition to historical information, forward-looking statements that
involve risks and uncertainties. Our actual results could differ materially.
Factors that could cause or contribute to such differences include, but are not
limited to, those discussed below, as well as those discussed elsewhere in this
prospectus, including the documents incorporated by reference.

There are risks associated with investing in companies such as ours who
are engaged in research and development.  Because of these risks, you
should only invest if you are able to bear the risk of losing your entire
investment.  Before investing, in addition to risks which could apply to
any issuer or offering, you should also consider the business we are in
and the following:

Research Frontiers has a history of operating losses, expects to incur
additional losses in the future, and consequently will need additional
funds in the future to continue its operations.  To date, Research
Frontiers has lost money, and we expect to lose money in the
foreseeable future.  Because we expect that our future revenues will
consist primarily of license fees (which have not been significant to date),
unless our licensees produce and sell products using our technology,
Research Frontiers will not be profitable. There is no guarantee
that we will ever be profitable. Since Research Frontiers was started
in 1965 through December 31, 2009, its total net loss was $76,399,353.
Our net loss was $4,002,761 in 2009, $2,594,843 in 2008, and
$7,565,218 in 2007 (which includes a non-cash accounting charge in
2007 of $4,026,855 resulting from the  expensing of stock options).

We have funded our operations by selling our common stock to investors.
If we need additional money, there is no guarantee that it will be available
when we need it, or on favorable terms. The Company will need to raise
additional capital no later than the first quarter of 2011 if operations,
including research and development and marketing, are to be maintained
at current levels and if its revenues do not increase before then. If
the Company cannot raise additional funds, it will be required to reduce
expenses during 2010. Eventual success of the Company and generation of
positive cash flow will be dependent upon the extent of commercialization
of products using the Company's technology by the Company's licensees
and payments of continuing royalties on account thereof.

Research Frontiers depends upon the activities of its licensees in order
to be profitable.  We do not directly manufacture or market products
using SPD technology.  Although a variety of products have been sold by our
licensees, and because it is up to our licensees to decide when and if they
will introduce products using SPD technology, we cannot predict when
and if our licensees will generate substantial sales of such products.
Research Frontiers' SPD technology is currently licensed to 37 companies.
Other companies are also evaluating SPD technology for use in various
products. In the past, some companies have evaluated our technology
without proceeding further.  Also, we do not intend to manufacture
products using SPD technology.  Instead we intend to continue to
license our SPD technology to manufacturers of end products, films
and emulsion. We expect that our licensees would be primarily
responsible for manufacturing and marketing SPD products and components,
but we are also engaging in market development activities to support our
licensees and build the smart glass industry.

Products using SPD technology have only recently begun to be introduced into
the marketplace.  Developing products using new technologies can be risky
because problems, expenses and delays frequently occur, and costs may
or may not come down quickly for such products using new technologies
to rapidly penetrate mass market applications.  Research Frontiers
cannot control whether or not its licensees will develop SPD products.
Some of our licensees appear to be more active than others, some
appear to be better capitalized than others, and some licensees appear
to be inactive. There is no guarantee when or if our licensees will
successfully produce any commercial product using SPD technology in
sufficient quantities to make Research Frontiers profitable.

Because SPD technology is the only technology Research Frontiers works
with, our success depends upon the viability of SPD technology which has
yet to be fully proven. We have not fully ascertained the performance and
long-term reliability of our technology, and therefore there is no
guarantee that our technology will successfully be incorporated into all
of the products which we are targeting for use of SPD technology. We
expect that different product applications for SPD technology will have
different performance and reliability specifications.  We expect that our
licensees will primarily be responsible for reliability testing, but that
we may also continue to do reliability testing so that we can more
effectively focus our research and development efforts towards constantly
improving the performance characteristics and reliability of products
using SPD technology.

                       AVAILABLE INFORMATION

Research Frontiers files reports, proxy statements and other information
with the Securities and Exchange Commission. You may read and copy
such reports, proxy statements and other information at the public
reference room maintained by the SEC at 100 F Street, N.E.,
Washington, D.C. 20549 and you can obtain information on the operation
of the Public Reference Room by calling the SEC at 1-800-SEC-0330.
The SEC also maintains an internet web site at http://www.sec.gov
that contains reports, proxy and information statements and other
information regarding issuers,  such as Research Frontiers, that
file electronically with the SEC.  Additional information about us
can also be found at our web site at http://www.SmartGlass.com.

The SEC allows us to incorporate by reference the information we file
with them, which means that we can disclose important information to
you by referring you to those documents.  The information incorporated
by reference is considered to be part of this prospectus, and later
information that we file with the SEC will automatically update and
supersede this information.  We incorporate by reference into this
prospectus our:

o   annual report on Form 10-K for the fiscal year ended December 31, 2008,

o   the portions of the proxy statement dated April 30, 2009 for our
    annual meeting of stockholders held on June 11, 2009 that
    have been incorporated by reference into our report on Form 10-K
    for the fiscal year ended December 31, 2008,
o   quarterly report on Form 10-Q for the fiscal quarter
    ended March 31, 2009,June 30, 2009 and September 30, 2009,
o   current reports on Form 8-K filed with the SEC on 2/11/09, 3/2/09,
    4/1/09, 4/30/09, 5/11/09,6/12/09,6/15/09,6/16/09,7/29/09,8/3/09,
    9/4/09, 9/15/09,10/23/09,10/27/09,10/228/09,11/12/09,12/16/09,12/18/09,
    1/25/10 and 2/16/10, and
o   the description of the capital stock contained in the Research Frontiers
    registration statements on Form 8-A under the Securities Exchange Act of
    1934 dated July 31, 1995 and February 24, 2003.

All filings filed by Research Frontiers with the SEC under Sections 13(a),
13(c), 14, or 15(d) of the Exchange Act subsequent to the initial filing of
this prospectus and prior to the termination of the offering or sale of
all of common stock offered under this prospectus shall be deemed to
be incorporated by reference into this prospectus.

This prospectus is part of a registration statement we filed with the SEC.
As permitted by the SEC, this prospectus does not contain all of the
information set forth in the registration statement and the exhibits and
schedules thereto.  The statements contained in this prospectus as to the
contents of any contract or any other document are not necessarily
complete.  In each case you should refer to the copy of such contract or
document filed as an exhibit to the registration statement.

We will provide each person to whom this prospectus is delivered, a
copy of any information we have incorporated by reference but have not
delivered along with this prospectus. If you would like a copy of any
document incorporated herein by reference, other than exhibits unless
such exhibits are specifically incorporated by reference in any such
document, you can call or write to us at our  principal executive offices:
240 Crossways Park Drive, Woodbury, New York 11797-2033,
Attention: Corporate Secretary (telephone: (516) 364-1902). We will
provide this information without charge to any person, including a
beneficial owner, to whom a copy of this prospectus is delivered upon
written or oral request.

No dealer, salesperson or other individual has been authorized to give
any information or to make any representation not contained in or
incorporated by reference in this prospectus or in any supplement to this
prospectus.  If given or made, you must not rely on such information or
representation as having been authorized by Research Frontiers. Neither
the delivery of this prospectus nor any sale made hereunder will,
under any circumstances, create an implication that there has not been
any change in the affairs of Research Frontiers since the date of this
prospectus or that the information contained herein is correct
or complete as of any time after the date of this prospectus.

This prospectus and any supplement to this prospectus do not constitute
an offer to sell or a solicitation of an offer to buy any securities offered
hereby to any person, or by anyone, in any jurisdiction in which such
offer or solicitation may not lawfully be made.

The information set forth herein and in all publicly disseminated
information about Research Frontiers, includes "forward-looking
statements" within the meaning of Section 21E of the Securities
Exchange Act of 1934, as amended, and is subject to the safe harbor
created by that section. Readers are cautioned not to place undue
reliance on these forward-looking statements as they speak only as of the
date of this prospectus and are not guaranteed.

                             DIVIDENDS

Research Frontiers has never paid any cash dividends and does not
expect to pay any cash dividends for the foreseeable future.

                          USE OF PROCEEDS

We currently intend to use the net proceeds from this offering for general
corporate purposes, including our internal research and development
programs, general working capital and possible future acquisitions.

We have not determined the amounts we plan to spend on any of the areas listed
above or the timing of these expenditures. As a result, our management will have
broad discretion to allocate the net proceeds from this offering. Pending
application of the net proceeds as described above, we intend to invest the net
proceeds of the offering in money market funds and other interest-bearing
investments.

                    DESCRIPTION OF SECURITIES

   We may sell from time to time, in one or more offerings common stock and/or
warrants to purchase common stock.

DESCRIPTION OF COMMON STOCK

Research Frontiers can issue 100,000,000 shares of common stock,
$0.0001 par value per share. 16,522,727 shares were outstanding as of
the date of this prospectus and prior to giving effect to the share
issued in this offering.  Holders of common stock are entitled to one
vote per share on matters submitted to shareholders for their approval, to
dividends if declared by Research Frontiers, and to share in any
distribution of Research Frontiers' assets.  All outstanding shares of
common stock are fully paid for and non-assessable.  Holders of
common stock do not have cumulative voting rights or preemptive
rights.  Therefore, a minority stockholder may be less able to gain
representation on Research Frontiers' board of directors.

Listing

Our common stock is listed on the Nasdaq Capital Market under the symbol "REFR".

Transfer Agent and Registrar

Continental Stock Transfer and Trust Company is the transfer agent and registrar
for our common stock.

DESCRIPTION OF WARRANTS

Each purchaser in this offering will receive a warrant
to purchase one share of our common stock for every five
shares of common stock purchased in this offering. The
warrants will be issued pursuant to warrant agreements
executed by us.

Each warrant will entitle the holder to purchase one share
of common stock at an exercise price of $5.00 per share.
Holders of the warrants may exercise the warrants at any
time from March 1, 2010 to 4:30 P.M. Woodbury, New York
time on February 28, 2015, after which unexercised warrants
will become void.

Holders of the warrants may exercise the warrants by delivering
the warrant certificate representing the warrants to be exercised
together with specified information, and paying the required
amount to the Company in immediately available cash funds. Upon
receipt of the required payment and the warrant certificate
properly completed and duly executed, we will issue and deliver
the number of shares of common stock purchasable upon such
exercise. If fewer than all of the warrants represented by the
warrant certificate are exercised, then we will issue a new
warrant certificate for the remaining amount of warrants.

The Warrants provide that unless a holder waives the provision,
the warrantholder may not exercise the warrant to the extent
that such execise will cause the warrantholder to beneficially
own more than 4.999% of the common stock of the Company
then outstanding. In no event may a warrantholder exercise
warrants if such exercise shall cause the warrantholder to
own more than 9.999% of the common stock of the Company
then outstanding.

The exercise price and the number and type of securities
purchasable upon exercise of warrants are subject to
adjustment upon certain corporate events, including certain
combinations, consolidations, liquidations, mergers,
recapitalizations, reclassifications, reorganizations,
stock dividends and stock splits, a sale of all or
substantially all of our assets and certain other events.

No fractional warrant shares will be issued upon exercise
of the warrants. Before exercising their warrants, holders
of warrants will not have any of the rights of holders of
common stock, including the right to receive dividends,
if any, or, payments upon our liquidation, dissolution or
winding up or to exercise voting rights, if any.

                       PLAN OF DISTRIBUTION

The Company directly placed the Units with the purchasers
without a placement agent.

Each Unit consists of one share and one-fifth of a warrant
to purchase common stock at an exercise price of $5.00
per share.  Assuming that the warrants are not exercised,
the Company will receive gross proceeds of $1,618,653 from
the sale of 588,602 shares of Common Stock at a price of
$2.75 per share. Investors also received 117,719 Warrants
in this offering.

The form of Subscription Agreement and Warrant Agreement are included
as exhibits to our Current Report on Form 8-K that was filed
with the Securities and Exchange Commission on March 3, 2010.

The transfer agent for our common stock is Continental Stock
Transfer & Trust Company.

Our common stock is traded on the Nasdaq Capital Market
under the symbol "REFR".



------------------------------------------------------------------------
FILED PURSUANT TO RULE 424(b)(2)
REGISTRATION NO. 333-159093


               PROSPECTUS SUPPLEMENT DATED AUGUST 3,2009
                   TO PROSPECTUS DATED MAY 8,2009

This prospectus is not an offer to sell these securities and it is not
soliciting an offer to buy these securities in any state where the offer
or sale is not permitted.


                  RESEARCH FRONTIERS INCORPORATED

                       780,831 Shares of Common Stock

       156,161 Warrants to Purchase Common Stock at $6.00 per Share

                               -------------------


                           -------------------


Research Frontiers Incorporated is selling to accredited investors a total of
780,831 shares of common stock and warrants expiring July 31, 2014
to purchase 156,161 shares of common stock at an exercise price of $6.00
per share.  This offering is part of a "shelf" registration statement that
we have filed with the Securities and Exchange Commission which was declared
effective by the SEC on May 28, 2009.The shelf registration statement covers
the issuance of up to 3,000,000 shares of common stock, and/or warrants to
purchase such common stock. Each time that we sell our securities under the
registration statement, we will issue a prospectus supplement like this one,
which includes the terms of the offering such as the price, terms and amount
of securities being sold. We may sell these securities to or through
underwriters and also to other purchasers or through agents. We will set
forth the names of any underwriters or agents in the accompanying
prospectus supplement.

    Our common stock is listed on the Nasdaq Capital Market under the
symbol "REFR." The last reported sale price of our common stock on the
Nasdaq Capital Market on July 31, 2009 was $3.85.

                               -------------------

     Investing in our common stock involves a high degree of risk. See "Risk
Factors" beginning on page 3.

                               -------------------

     Neither the Securities and Exchange Commission nor any State Securities
Commission has approved or disapproved of these securities or determined if this
prospectus is truthful or complete. Any representation to the contrary is a
criminal offense.

                               -------------------

                              Per Unit(1)         Total Offering
Public Offering Price:             $3.65           $2,850,000.00
Proceeds, before expenses, to us:  $3.65           $2,850,000.00

(1) Each Unit consists of one share and one-fifth of a warrant expiring
    July 31, 2014 to purchase common stock at an exercise price of
    $6.00 per share.

Delivery of the shares of common stock and warrants to the purchasers
is expected to be made on or about August 4, 2009.


   The date of this prospectus supplement is August 3,2009



                  ABOUT THIS PROSPECTUS SUPPLEMENT

This prospectus supplement and the accompanying base prospectus dated
May 8, 2009 are part of a "shelf" registration statement that we
have filed with the Securities and Exchange Commission, or SEC. Each time
we sell securities under the accompanying base prospectus we will
provide a prospectus supplement that will contain specific information
about the terms of that offering, including the price, the amount of
common stock being offered and the plan of distribution. The shelf
registration was declared effective by the SEC on May 28, 2009.
This prospectus supplement describes the specific details regarding
this offering, including the price, the amount of common stock being
offered, the risks of investing in our common stock and the plan
of distribution. The accompanying base prospectus provides general
information about us, some of which, such as the section entitled
"Plan of Distribution," may not apply to this offering.

If information in this prospectus supplement is inconsistent with
the accompanying base prospectus or the information incorporated
by reference, you should rely on this prospectus supplement. You
should read both this prospectus supplement and the accompanying
base prospectus together with the additional information about
Research Frontiers Incorporated to which we refer you in the
section of this prospectus supplement entitled "Available Information."


                              SUMMARY

         You should read the entire prospectus, including the section entitled
'Risk Factors,' carefully before making an investment decision.

                            THE COMPANY

     Research Frontiers Incorporated ("Research Frontiers" or the
"Company") develops and licenses its suspended particle technology for
controlling the amount of light passing through a device. Such
suspended particle devices are often referred to as "SPDs," "light
valves," or "SPD-Smart " products.

     SPDs use microscopic light-absorbing particles that are either in
a liquid suspension or a film. The microscopic particles align when an
electrical voltage is applied.  This permits light to pass through the
device, and allows the amount of light to be controlled. Our offices
are located at: 240 Crossways Park Drive, Woodbury, NY 11797
(telephone: 516-364-1902).

                            THE OFFERING

Common Stock issued by Research Frontiers:     780,831 shares
Common Stock Outstanding after this offering:  16,522,727 shares
Warrants exercisable at $6.00 per share:       156,161 warrants
Use of Proceeeds:                              general corporate purposes
Nasdaq Capital Market Symbol:                  REFR

The number of shares of common stock outstanding after this offering is
based upon 15,741,896 shares outstanding as of July 31,2009. It
excludes outstanding options and warrants (not including the
warrants issued in this offering) to purchase 2,232,180
shares of common stock, and options or other equity awards for
450,938 shares available for future issuance pursuant to the
Company's 2008 Equity Incentive Plan.

                           RISK FACTORS

         In addition to the other information in this prospectus, you should
carefully consider the following factors in evaluating us and our business
before purchasing the shares of common stock offered hereby. This prospectus
contains, in addition to historical information, forward-looking statements that
involve risks and uncertainties. Our actual results could differ materially.
Factors that could cause or contribute to such differences include, but are not
limited to, those discussed below, as well as those discussed elsewhere in this
prospectus, including the documents incorporated by reference.

There are risks associated with investing in companies such as ours who
are engaged in research and development.  Because of these risks, you
should only invest if you are able to bear the risk of losing your entire
investment.  Before investing, in addition to risks which could apply to
any issuer or offering, you should also consider the business we are in
and the following:

Research Frontiers has a history of operating losses, expects to incur
additional losses in the future, and consequently will need additional
funds in the future to continue its operations.  To date, Research
Frontiers has lost money, and we expect to lose money in the
foreseeable future.  Because we expect that our future revenues will
consist primarily of license fees (which have not been significant to date),
unless our licensees produce and sell products using our technology,
Research Frontiers will not be profitable. There is no guarantee
that we will ever be profitable. Since Research Frontiers was started
in 1965 through December 31, 2008, its total net loss was $72,396,592.
Our net loss was $2,594,843 in 2008, $7,565,218 in 2007 (which includes
a non-cash accounting charge of $4,026,855 resulting from the
expensing of stock options), and $3,303,633 in 2006.

We have funded our operations by selling our common stock to investors.
If we need additional money, there is no guarantee that it will be available
when we need it, or on favorable terms. The Company will need to raise
additional capital no later than the first quarter of 2010 if operations,
including research and development and marketing, are to be maintained
at current levels and if its revenues do not increase before then. If
the Company cannot raise additional funds, it will be required to reduce
expenses during 2009. Eventual success of the Company and generation of
positive cash flow will be dependent upon the extent of commercialization
of products using the Company's technology by the Company's licensees
and payments of continuing royalties on account thereof.

Research Frontiers depends upon the activities of its licensees in order
to be profitable.  We do not directly manufacture or market products
using SPD technology.  Although a variety of products have been sold by our
licensees, and since it is up to our licensees to decide when and if they
will introduce products using SPD technology, we cannot predict when
and if our licensees will generate substantial sales of such products.
Research Frontiers' SPD technology is currently licensed to 35 companies.
Other companies are also evaluating SPD technology for use in various
products. In the past, some companies have evaluated our technology
without proceeding further.  Also, we do not intend to manufacture
products using SPD technology.  Instead we intend to continue to
license our SPD technology to manufacturers of end products, films
and emulsion. We expect that our licensees would be primarily
responsible for manufacturing and marketing SPD products and components,
but we are also engaging in market development activities to support our
licensees and build the smart glass industry.

Products using SPD technology have only recently begun to be introduced into
the marketplace.  Developing products using new technologies can be risky
because problems, expenses and delays frequently occur.  Research
Frontiers cannot control whether or not its licensees will develop SPD
products.  Some of our licensees appear to be more active than others, some
appear to be better capitalized than others, and some licensees appear
to be inactive. There is no guarantee when or if our licensees will
successfully produce any commercial product using SPD technology in
sufficient quantities to make Research Frontiers profitable.

Because SPD technology is the only technology Research Frontiers works
with, our success depends upon the viability of SPD technology which has
yet to be fully proven. We have not fully ascertained the performance and
long-term reliability of our technology, and therefore there is no
guarantee that our technology will successfully be incorporated into all
of the products which we are targeting for use of SPD technology. We
expect that different product applications for SPD technology will have
different performance and reliability specifications.  We expect that our
licensees will primarily be responsible for reliability testing, but that
we may also continue to do reliability testing so that we can more
effectively focus our research and development efforts towards constantly
improving the performance characteristics and reliability of products
using SPD technology.

                       AVAILABLE INFORMATION

Research Frontiers files reports, proxy statements and other information
with the Securities and Exchange Commission. You may read and copy
such reports, proxy statements and other information at the public
reference room maintained by the SEC at 100 F Street, N.E.,
Washington, D.C. 20549 and you can obtain information on the operation
of the Public Reference Room by calling the SEC at 1-800-SEC-0330.
The SEC also maintains an internet web site at http://www.sec.gov
that contains reports, proxy and information statements and other
information regarding issuers,  such as Research Frontiers, that
file electronically with the SEC.  Additional information about us
can also be found at our web site at http://www.SmartGlass.com.

The SEC allows us to incorporate by reference the information we file
with them, which means that we can disclose important information to
you by referring you to those documents.  The information incorporated
by reference is considered to be part of this prospectus, and later
information that we file with the SEC will automatically update and
supersede this information.  We incorporate by reference into this
prospectus our:

o   annual report on Form 10-K for the fiscal year ended December 31, 2008,

o   the portions of the proxy statement dated April 30, 2009 for our
    annual meeting of stockholders to be held on June 11, 2009 that
    have been incorporated by reference into our report on Form 10-K
    for the fiscal year ended December 31, 2008,
o   quarterly report on Form 10-Q for the fiscal quarter
    ended March 31, 2009,
o   current report on Form 8-K filed with the SEC on April 30, 2009,
    May 11, 2009, June 12, 2009, June 15, 2009, June 16, 2009, and
    July 29, 2009, and
o   the description of the capital stock contained in the Research Frontiers
    registration statements on Form 8-A under the Securities Exchange Act of
    1934 dated July 31, 1995 and February 24, 2003.

All filings filed by Research Frontiers with the SEC under Sections 13(a),
13(c), 14, or 15(d) of the Exchange Act subsequent to the initial filing of
this prospectus and prior to the termination of the offering or sale of
all of common stock offered under this prospectus shall be deemed to
be incorporated by reference into this prospectus.

This prospectus is part of a registration statement we filed with the SEC.
As permitted by the SEC, this prospectus does not contain all of the
information set forth in the registration statement and the exhibits and
schedules thereto.  The statements contained in this prospectus as to the
contents of any contract or any other document are not necessarily
complete.  In each case you should refer to the copy of such contract or
document filed as an exhibit to the registration statement.

We will provide each person to whom this prospectus is delivered, a
copy of any information we have incorporated by reference but have not
delivered along with this prospectus. If you would like a copy of any
document incorporated herein by reference, other than exhibits unless
such exhibits are specifically incorporated by reference in any such
document, you can call or write to us at our  principal executive offices:
240 Crossways Park Drive, Woodbury, New York 11797-2033,
Attention: Corporate Secretary (telephone: (516) 364-1902). We will
provide this information without charge to any person, including a
beneficial owner, to whom a copy of this prospectus is delivered upon
written or oral request.

No dealer, salesperson or other individual has been authorized to give
any information or to make any representation not contained in or
incorporated by reference in this prospectus or in any supplement to this
prospectus.  If given or made, you must not rely on such information or
representation as having been authorized by Research Frontiers. Neither
the delivery of this prospectus nor any sale made hereunder will,
under any circumstances, create an implication that there has not been
any change in the affairs of Research Frontiers since the date of this
prospectus or that the information contained herein is correct
or complete as of any time after the date of this prospectus.

This prospectus and any supplement to this prospectus do not constitute
an offer to sell or a solicitation of an offer to buy any securities offered
hereby to any person, or by anyone, in any jurisdiction in which such
offer or solicitation may not lawfully be made.

The information set forth herein and in all publicly disseminated
information about Research Frontiers, includes "forward-looking
statements" within the meaning of Section 21E of the Securities
Exchange Act of 1934, as amended, and is subject to the safe harbor
created by that section. Readers are cautioned not to place undue
reliance on these forward-looking statements as they speak only as of the
date of this prospectus and are not guaranteed.

                             DIVIDENDS

Research Frontiers has never paid any cash dividends and does not
expect to pay any cash dividends for the foreseeable future.

                          USE OF PROCEEDS

We currently intend to use the net proceeds from this offering for general
corporate purposes, including our internal research and development
programs, general working capital and possible future acquisitions.

We have not determined the amounts we plan to spend on any of the areas listed
above or the timing of these expenditures. As a result, our management will have
broad discretion to allocate the net proceeds from this offering. Pending
application of the net proceeds as described above, we intend to invest the net
proceeds of the offering in money market funds and other interest-bearing
investments.

                    DESCRIPTION OF SECURITIES

   We may sell from time to time, in one or more offerings common stock and/or
warrants to purchase common stock.

DESCRIPTION OF COMMON STOCK

Research Frontiers can issue 100,000,000 shares of common stock,
$0.0001 par value per share. 15,741,896 shares were outstanding as of
the date of this prospectus and prior to giving effect to the share
issued in this offering.  Holders of common stock are entitled to one
vote per share on matters submitted to shareholders for their approval, to
dividends if declared by Research Frontiers, and to share in any
distribution of Research Frontiers' assets.  All outstanding shares of
common stock are fully paid for and non-assessable.  Holders of
common stock do not have cumulative voting rights or preemptive
rights.  Therefore, a minority stockholder may be less able to gain
representation on Research Frontiers' board of directors.

Listing

Our common stock is listed on the Nasdaq Capital Market under the symbol "REFR".

Transfer Agent and Registrar

Continental Stock Transfer and Trust Company is the transfer agent and registrar
for our common stock.

DESCRIPTION OF WARRANTS

Each purchaser in this offering will receive a warrant
to purchase one share of our common stock for every five
shares of common stock purchased in this offering. The
warrants will be issued pursuant to warrant agreements
executed by us.

Each warrant will entitle the holder to purchase one share
of common stock at an exercise price of $6.00 per share.
Holders of the warrants may exercise the warrants at any
time from July 29, 2009 to 4:30 P.M. Woodbury, New York
time on July 31, 2014, after which unexercised warrants
will become void.

Holders of the warrants may exercise the warrants by delivering
the warrant certificate representing the warrants to be exercised
together with specified information, and paying the required
amount to the Company in immediately available cash funds. Upon
receipt of the required payment and the warrant certificate
properly completed and duly executed, we will issue and deliver
the number of shares of common stock purchasable upon such
exercise. If fewer than all of the warrants represented by the
warrant certificate are exercised, then we will issue a new
warrant certificate for the remaining amount of warrants.

The Warrants provide that unless a holder waives the provision,
the warrantholder may not exercise the warrant to the extent
that such execise will cause the warrantholder to beneficially
own more than 4.999% of the common stock of the Company
then outstanding. In no event may a warrantholder exercise
warrants if such exercise shall cause the warrantholder to
own more than 9.999% of the common stock of the Company
then outstanding.

The exercise price and the number and type of securities
purchasable upon exercise of warrants are subject to
adjustment upon certain corporate events, including certain
combinations, consolidations, liquidations, mergers,
recapitalizations, reclassifications, reorganizations,
stock dividends and stock splits, a sale of all or
substantially all of our assets and certain other events.

No fractional warrant shares will be issued upon exercise
of the warrants. Before exercising their warrants, holders
of warrants will not have any of the rights of holders of
common stock, including the right to receive dividends,
if any, or, payments upon our liquidation, dissolution or
winding up or to exercise voting rights, if any.

                       PLAN OF DISTRIBUTION

The Company directly placed the Units with the purchasers
without a placement agent.

Each Unit consists of one share and one-fifth of a warrant
to purchase common stock at an exercise price of $6.00
per share.  Assuming that the warrants are not exercised,
the Company will receive gross proceeds of $2,850,000 from
the sale of 780,831 shares of Common Stock at a price of
$3.65 per share. Investors also received 156,161 Warrants
in this offering.

The form of Subscription Agreement and Warrant Agreement are included
as exhibits to our Current Report on Form 8-K that was filed
with the Securities and Exchange Commission on August 3, 2009.

The transfer agent for our common stock is Continental Stock
Transfer & Trust Company.

Our common stock is traded on the Nasdaq Capital Market
under the symbol "REFR".


------------------------------------------------------------------------
This information in this prospectus is not complete and may be changed. We may
not sell these securities until the registration statement filed with the
Securities and Exchange Commission is effective. This prospectus is not an
offer to sell these securities and it is not soliciting an offer to buy these
securities in any state where the offer or sale is not permitted.




                                PROSPECTUS

                 SUBJECT TO COMPLETION, DATED MAY 8, 2009


                       RESEARCH FRONTIERS INCORPORATED

                               3,000,000 Shares

                                 Common Stock

                               -------------------


Research Frontiers Incorporated may from time to time issue up to 3,000,000
shares of  common stock, and/or warrants to purchase such common stock.
A general description of the known material terms of the securities we
are offering is included herein. We will specify in an accompanying prospectus
supplement any specific material terms of the securities offered which are
unknown as of the date of this prospectus. We may sell these securities to
or through underwriters and also to other purchasers or through agents.
We will set forth the names of any underwriters or agents in the
accompanying prospectus supplement.

    Our common stock is listed on the Nasdaq Capital Market under the
symbol "REFR." The last reported sale price of our common stock on the
Nasdaq Capital Market on May 7, 2009 was $3.13.

                               -------------------

     Investing in our common stock involves a high degree of risk. See 'Risk
Factors' beginning on page 3.

                               -------------------

     Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or determined if this
prospectus is truthful or complete. Any representation to the contrary is a
criminal offense.

This prospectus may not be used to consummate a sale of securities unless it is
accompanied by a prospectus supplement.

            The date of this prospectus is             , 2009


                              SUMMARY

         You should read the entire prospectus, including the section entitled
'Risk Factors,' carefully before making an investment decision.

                            THE COMPANY

     Research Frontiers Incorporated ("Research Frontiers" or the
"Company") develops and licenses its suspended particle technology for
controlling the amount of light passing through a device. Such
suspended particle devices are often referred to as "SPDs," "light
valves," or "SPD-Smart " products.

     SPDs use microscopic light-absorbing particles that are either in
a liquid suspension or a film. The microscopic particles align when an
electrical voltage is applied.  This permits light to pass through the
device, and allows the amount of light to be controlled. Our offices
are located at: 240 Crossways Park Drive, Woodbury, NY 11797
(telephone: 516-364-1902).

                           RISK FACTORS

         In addition to the other information in this prospectus, you should
carefully consider the following factors in evaluating us and our business
before purchasing the shares of common stock offered hereby. This prospectus
contains, in addition to historical information, forward-looking statements that
involve risks and uncertainties. Our actual results could differ materially.
Factors that could cause or contribute to such differences include, but are not
limited to, those discussed below, as well as those discussed elsewhere in this
prospectus, including the documents incorporated by reference.

There are risks associated with investing in companies such as ours who
are engaged in research and development.  Because of these risks, you
should only invest if you are able to bear the risk of losing your entire
investment.  Before investing, in addition to risks which could apply to
any issuer or offering, you should also consider the business we are in
and the following:

Research Frontiers has a history of operating losses, expects to incur
additional losses in the future, and consequently will need additional
funds in the future to continue its operations.  To date, Research
Frontiers has lost money, and we expect to lose money in the
foreseeable future.  Because we expect that our future revenues will
consist primarily of license fees (which have not been significant to date),
unless our licensees produce and sell products using our technology,
Research Frontiers will not be profitable. There is no guarantee
that we will ever be profitable. Since Research Frontiers was started
in 1965 through December 31, 2008, its total net loss was $72,396,592.
Our net loss was $2,594,843 in 2008, $7,565,218 in 2007 (which includes
a non-cash accounting charge of $4,026,855 resulting from the
expensing of stock options), and $3,303,633 in 2006.

We have funded our operations by selling our common stock to investors.
If we need additional money, there is no guarantee that it will be available
when we need it, or on favorable terms. The Company will need to raise
additional capital no later than the first quarter of 2010 if operations,
including research and development and marketing, are to be maintained
at current levels and if its revenues do not increase before then. If
the Company cannot raise additional funds, it will be required to reduce
expenses during 2009. Eventual success of the Company and generation of
positive cash flow will be dependent upon the extent of commercialization
of products using the Company's technology by the Company's licensees
and payments of continuing royalties on account thereof.

Research Frontiers depends upon the activities of its licensees in order
to be profitable.  We do not directly manufacture or market products
using SPD technology.  Although a variety of products have been sold by our
licensees, and since it is up to our licensees to decide when and if they
will introduce products using SPD technology, we cannot predict when
and if our licensees will generate substantial sales of such products.
Research Frontiers' SPD technology is currently licensed to 35 companies.
Other companies are also evaluating SPD technology for use in various
products. In the past, some companies have evaluated our technology
without proceeding further.  Also, we do not intend to manufacture
products using SPD technology.  Instead we intend to continue to
license our SPD technology to manufacturers of end products, films
and emulsion. We expect that our licensees would be primarily
responsible for manufacturing and marketing SPD products and components,
but we are also engaging in market development activities to support our
licensees and build the smart glass industry.

Products using SPD technology have only recently begun to be introduced into
the marketplace.  Developing products using new technologies can be risky
because problems, expenses and delays frequently occur.  Research
Frontiers cannot control whether or not its licensees will develop SPD
products.  Some of our licensees appear to be more active than others, some
appear to be better capitalized than others, and some licensees appear
to be inactive. There is no guarantee when or if our licensees will
successfully produce any commercial product using SPD technology in
sufficient quantities to make Research Frontiers profitable.

Because SPD technology is the only technology Research Frontiers works
with, our success depends upon the viability of SPD technology which has
yet to be fully proven. We have not fully ascertained the performance and
long-term reliability of our technology, and therefore there is no
guarantee that our technology will successfully be incorporated into all
of the products which we are targeting for use of SPD technology. We
expect that different product applications for SPD technology will have
different performance and reliability specifications.  We expect that our
licensees will primarily be responsible for reliability testing, but that
we may also continue to do reliability testing so that we can more
effectively focus our research and development efforts towards constantly
improving the performance characteristics and reliability of products
using SPD technology.

                       AVAILABLE INFORMATION

Research Frontiers files reports, proxy statements and other information
with the Securities and Exchange Commission. You may read and copy
such reports, proxy statements and other information at the public
reference room maintained by the SEC at 100 F Street, N.E.,
Washington, D.C. 20549 and you can obtain information on the operation
of the Public Reference Room by calling the SEC at 1-800-SEC-0330.
The SEC also maintains an internet web site at http://www.sec.gov
that contains reports, proxy and information statements and other
information regarding issuers,  such as Research Frontiers, that
file electronically with the SEC.  Additional information about us
can also be found at our web site at http://www.SmartGlass.com.

The SEC allows us to incorporate by reference the information we file
with them, which means that we can disclose important information to
you by referring you to those documents.  The information incorporated
by reference is considered to be part of this prospectus, and later
information that we file with the SEC will automatically update and
supersede this information.  We incorporate by reference into this
prospectus our:

o   annual report on Form 10-K for the fiscal year ended December 31, 2008,
o   the portions of the proxy statement dated April 30, 2009 for our
    annual meeting of stockholders to be held on June 11, 2009 that
    have been incorporated by reference into our report on Form 10-K
    for the fiscal year ended December 31, 2008,
o   current report on Form 8-K filed with the SEC on April 30, 2009, and
o   the description of the capital stock contained in the Research Frontiers
    registration statements on Form 8-A under the Securities Exchange Act of
    1934 dated July 31, 1995 and February 24, 2003.

All filings filed by Research Frontiers with the SEC under Sections 13(a),
13(c), 14, or 15(d) of the Exchange Act subsequent to the initial filing of
this prospectus and prior to the termination of the offering or sale of
all of common stock offered under this prospectus shall be deemed to
be incorporated by reference into this prospectus.

This prospectus is part of a registration statement we filed with the SEC.
As permitted by the SEC, this prospectus does not contain all of the
information set forth in the registration statement and the exhibits and
schedules thereto.  The statements contained in this prospectus as to the
contents of any contract or any other document are not necessarily
complete.  In each case you should refer to the copy of such contract or
document filed as an exhibit to the registration statement.

We will provide each person to whom this prospectus is delivered, a
copy of any information we have incorporated by reference but have not
delivered along with this prospectus. If you would like a copy of any
document incorporated herein by reference, other than exhibits unless
such exhibits are specifically incorporated by reference in any such
document, you can call or write to us at our  principal executive offices:
240 Crossways Park Drive, Woodbury, New York 11797-2033,
Attention: Corporate Secretary (telephone: (516) 364-1902). We will
provide this information without charge to any person, including a
beneficial owner, to whom a copy of this prospectus is delivered upon
written or oral request.

No dealer, salesperson or other individual has been authorized to give
any information or to make any representation not contained in or
incorporated by reference in this prospectus or in any supplement to this
prospectus.  If given or made, you must not rely on such information or
representation as having been authorized by Research Frontiers. Neither
the delivery of this prospectus nor any sale made hereunder will,
under any circumstances, create an implication that there has not been
any change in the affairs of Research Frontiers since the date of this
prospectus or that the information contained herein is correct
or complete as of any time after the date of this prospectus.

This prospectus and any supplement to this prospectus do not constitute
an offer to sell or a solicitation of an offer to buy any securities offered
hereby to any person, or by anyone, in any jurisdiction in which such
offer or solicitation may not lawfully be made.

The information set forth herein and in all publicly disseminated
information about Research Frontiers, includes "forward-looking
statements" within the meaning of Section 21E of the Securities
Exchange Act of 1934, as amended, and is subject to the safe harbor
created by that section. Readers are cautioned not to place undue
reliance on these forward-looking statements as they speak only as of the
date of this prospectus and are not guaranteed.

                             DIVIDENDS

Research Frontiers has never paid any cash dividends and does not
expect to pay any cash dividends for the foreseeable future.

                          USE OF PROCEEDS

Unless we indicate otherwise in the applicable prospectus supplement,
we currently intend to use the net proceeds from this offering for general
corporate purposes, including our internal research and development
programs, general working capital and possible future acquisitions.

We have not determined the amounts we plan to spend on any of the areas listed
above or the timing of these expenditures. As a result, our management will have
broad discretion to allocate the net proceeds from this offering. Pending
application of the net proceeds as described above, we intend to invest the net
proceeds of the offering in money market funds and other interest-bearing
investments.

                    DESCRIPTION OF SECURITIES

   We may sell from time to time, in one or more offerings common stock and/or
warrants to purchase common stock.

DESCRIPTION OF COMMON STOCK

Research Frontiers can issue 100,000,000 shares of common stock,
$0.0001 par value per share. 15,742,784 shares were outstanding as of
the date of this prospectus.  Holders of common stock are entitled to one
vote per share on matters submitted to shareholders for their approval, to
dividends if declared by Research Frontiers, and to share in any
distribution of Research Frontiers' assets.  All outstanding shares of
common stock are fully paid for and non-assessable.  Holders of
common stock do not have cumulative voting rights or preemptive
rights.  Therefore, a minority stockholder may be less able to gain
representation on Research Frontiers' board of directors.

Listing

Our common stock is listed on the Nasdaq Capital Market under the symbol "REFR".

Transfer Agent and Registrar

Continental Stock Transfer and Trust Company is the transfer agent and registrar
for our common stock.

DESCRIPTION OF WARRANTS

The following description sets forth certain general terms and provisions of
the warrants to which any prospectus supplement may relate. The particular terms
of the warrants offered, the extent, if any, to which the general terms set
forth below apply to the warrants offered, and any modifications or additions to
the general terms as they relate to the warrants offered will be described in a
prospectus supplement.

General

We may issue warrants for the purchase of common stock from
time to time, and we may issue warrants independently or
together with common stock, and the warrants may be attached
to or separate from these securities.

We will describe in the applicable prospectus supplement the
terms of the series of warrants, including:

-the offering price and aggregate number of warrants offered;

-the number of shares of common stock purchasable upon the
exercise of one warrant and the price at which these shares may
be purchased upon such exercise;

-the dates on which the right to exercise the warrants will
commence and expire;

-the effect of any merger, consolidation, sale or other disposition
of our business on the warrant agreement and the warrants;

-the terms of any rights to redeem or call the warrants;

-any provisions for changes to or adjustments in the exercise
price or number of securities issuable upon exercise of the
warrants;

-to the extent material,federal income tax consequences of
holding or exercising the warrants;

-any other specific terms, preferences, rights or limitations of or
restrictions on the warrants.

Before exercising their warrants, holders of warrants will not
have any of the rights of holders of common stock, including
the right to receive dividends, if any, or, payments upon our
liquidation, dissolution or winding up or to exercise voting
rights, if any.

Exercise of Warrants

Each warrant will entitle the holder to purchase the securities
that we specify in the applicable prospectus supplement at the
exercise price that we describe in the applicable prospectus
supplement. Unless we otherwise specify in the applicable
prospectus supplement, holders of the warrants may exercise the
warrants at any time up to 6:00 P.M. Woodbury, New York time
on the expiration date that we set forth in the applicable
prospectus supplement. After the close of business on the
expiration date, unexercised warrants will become void.

Holders of the warrants may exercise the warrants by delivering
the warrant certificate representing the warrants to be exercised
together with specified information, and paying the required
amount to the Company in immediately available funds. Upon
receipt of the required payment and the warrant certificate
properly completed and duly executed, we will issue and deliver
the number of shares of common stock purchasable upon such
exercise. If fewer than all of the warrants represented by the
warrant certificate are exercised, then we will issue a new
warrant certificate for the remaining amount of warrants. Unless
we indicate otherwise in the applicable prospectus supplement,
holders of the warrants may surrender securities as all or part of
the exercise price for warrants.

                       PLAN OF DISTRIBUTION

We may sell the securities being offered hereby in one or more
of the following ways from time to time:

-through dealers or agents to the public or to investors;

-to underwriters for resale to the public or to investors;

- directly to investors; or

- through a combination of such methods.

We will set forth in a prospectus supplement the terms of the
offering of securities, including:

- the name or names of any agents, dealers or underwriters;

- the purchase price of the securities being offered and the
proceeds we will receive from the sale;

- any over-allotment options under which underwriters may
purchase additional securities from us;

-  any agency fees or underwriting discounts and other items
constituting agents' or underwriters' compensation;

- any initial public offering price;

- any discounts or concessions allowed or reallowed or paid to
dealers; and

 - any securities exchanges on which the securities may be listed
   if it is other than the Nasdaq Capital Market.

Underwriters, dealers and agents that participate in the
distribution of the securities may be deemed to be underwriters
as defined in the Securities Act and any discounts or
commissions they receive from us and any profit on their resale
of the securities may be treated as underwriting discounts and
commissions under the Securities Act. We will identify in the
applicable prospectus supplement any underwriters, dealers or
agents and will describe their compensation. We may have
agreements with the underwriters, dealers and agents to
indemnify them against specified civil liabilities, including
liabilities under the Securities Act. Underwriters, dealers and
agents may engage in transactions with or perform services for
us or our subsidiaries in the ordinary course of their businesses.
Certain persons that participate in the distribution of the
securities may engage in transactions that stabilize, maintain or
otherwise affect the price of the securities, including
over-allotment, stabilizing and short-covering transactions in
such securities, and the imposition of penalty bids, in
connection with an offering. Certain persons may also engage in
passive market making transactions as permitted by Rule 103 of
Regulation M. Passive market makers must comply with applicable
volume and price limitations and must be identified as passive
market makers. In general, a passive market maker must display
its bid at a price not in excess of the highest independent bid
for such security; if all independent bids are lowered below
the passive market maker's bid, however, the passive market
maker's bid must then be lowered when certain purchase
limits are exceeded.

                              EXPERTS

The financial statements and schedule of Research Frontiers as of
December 31, 2008 and 2007, and for each of the three years in
the period ended December 31, 2008, and management's assessment
of the effectiveness over internal controls as of December 31, 2008,
incorporated by reference into this prospectus have been so
incorporated in reliance upon the reports of BDO Seidman, LLP,
an independent registered public accounting firm, incorporated
herein by reference, given on the authority of said firm as
experts in accounting and auditing.

                           LEGAL MATTERS

     The legality of the securities offered hereby has been passed upon by
Joseph M. Harary, Esq., the President and General Counsel.  As of May 7,
2009, Mr. Harary holds common stock and options to purchase common stock
granted pursuant to the Company's 1992 Stock Option Plan, 1998 Stock Option
Plan, and 2008 Equity Incentive Plan totaling 663,341 shares.