photochromic

adjective

pho·​to·​chro·​mic ˌfō-tə-ˈkrō-mik 

1

: capable of changing color on exposure to radiant energy (such as light)

photochromic glass

2

: of, relating to, or utilizing the change of color shown by a photochromic substance

a photochromic process

photochromism

ˌfō-tə-ˈkrō-ˌmi-zəm 

noun

Examples of photochromic in a Sentence

Recent Examples on the Web

And yes, photochromic transition lenses do already change tint automatically. —Ben Coxworth, New Atlas, 5 Nov. 2024

Designed for bike racing, the Density is just as ideal for nordic skiing, thanks to its huge field of vision, arms made from soft-gripping rubber derived from castor beans that can be bent in multiple ways for a custom fit, and photochromic lenses that adjust to whatever light is on the trail. —Stephanie Pearson, Outside Online, 10 Oct. 2024

The lenses are crafted from either photochromic crystal or polyamide to enhance UV protection. —Max Berlinger, Robb Report, 26 Mar. 2024

Using photochromic particles that react to UV light, the molecular structure — and therefore outward appearance — of Magic Ink can be altered by specific light wavelengths. —Leah Dolan, CNN, 5 Feb. 2024

Word History

Etymology

phot- + chrom- + -ic entry 1

First Known Use

1881, in the meaning defined at sense 1

Medical Definition

photochromic

1 of 2 adjective

pho·​to·​chro·​mic ˌfōt-ə-ˈkrō-mik 

1

: capable of changing color on exposure to radiant energy (as light)

eyeglasses with photochromic lenses

2

: of, relating to, or utilizing the change of color shown by a photochromic substance

a photochromic process

photochromism

-ˌmiz-əm 

noun

photochromic

2 of 2 noun

: a photochromic substance

—usually used in plural