Crosswords Solver

Answer: photochromic
Answer	Crossword Clue
photochromic	changing colour, and hence changing the amount of light transmitted when the incident light increases, or decreases / a photochromic material
photochromic	(of a substance) Undergoing a reversible change in color or shade when exposed to light of a particular frequency or intensity

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.

Answer: photochromic