Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4826977 | Photochromic spiropyran compounds | Harry G. Heller, John Whittall, Ian A. Tomlinson | 1989-05-02 |
| 4818096 | Photoreactive lenses with adamantane spiro compounds | Harry G. Heller, John Whittall, Jack Brettle, Clive Trundle, Martin W. Baskerville | 1989-04-04 |