| # | Clue | Answer As Given | Value | Round | Category | Air Date | Show |
|---|---|---|---|---|---|---|---|
| This transparent structure behind the iris focuses light entering the eye | the lens | $200 | J | SCIENCE | 2012-01-31 | #6302 | |
| The focal length is the distance from the center of one of these to the focal point | the lens | $300 | J | SCIENCE | 1996-10-03 | #2779 |