| Answer | Crossword Clue |
|---|---|
| fresnels | A flat lens made of a number of concentric rings, to reduce spherical aberration |
| Answer | Crossword Clue |
|---|---|
| fresnels | A flat lens made of a number of concentric rings, to reduce spherical aberration |
Crossword
a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.