OPTICAL
| Date | Clue |
|---|---|
| 2025-09-18 | Kind of illusion |
| 2025-01-16 | Vision-related |
| 2020-02-05 | Like some illusions |
| 2016-06-10 | Like spectroscopes and microscopes |
| 2014-10-20 | ___ illusion |
| 2010-08-21 | Kind of mouse |
| 2010-01-09 | Like some thin fibers |
| 2008-09-25 | Kind of scanner |
| 2005-01-22 | Kind of glass |
| 2000-01-02 | Kind of scanner |
| 1997-10-31 | Re sight |