Registration No.  333-65219
      Filed under Section 424(b)(3) pursuant to Section 424(c)(2)

                     Prospectus Supplement #3

This prospectus supplement applies to the prospectus dated May
21, 1999 filed as part of the Registration Statement on Form S-3
(Registration No.  333-65219).

When Research Frontiers filed its registration statement of
which this prospectus is a part, we registered a total of
2,331,000 shares of common stock to be sold under this
prospectus. Although we are not planning to issue any more
stock than the 2,331,000 shares covered by this prospectus,
because the selling price of our common stock has increased
since the class A warrant was issued, we have not issued as
much stock as originally anticipated under the class A warrant
held by Ailouros, Ltd. The class A warrant was scheduled to
expire on December 31, 2003.  Because of this, Research
Frontiers and the underwriter, Ailouros Ltd., agreed to extend
the expiration date of the class A warrant until December 31,
2005. The plan of distribution for these shares remains the same
as originally disclosed in our May 21, 1999 prospectus.