Across
- 3. a mirror with a flat reflective surface
- 5. a thing that doesn't let light pass through
- 6. I
- 8. it occurs in a optical fiber
- 10. R
- 12. instrument to see in the human body
Down
- 1. a ray that is reflected from a surface
- 2. Thin thread made of glass
- 4. a measurement of how much the light slows down entering in a dense mirror
- 7. Imaginary line perpendicular to the mirror
- 9. Changes in medium density cause this
- 11. unit of measure of light intensity