# photochromic lens

> optical lenses that darken on exposure to certain wavelengths of light

**Wikidata**: [Q2737181](https://www.wikidata.org/wiki/Q2737181)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Photochromic_lens)  
**Source**: https://4ort.xyz/entity/photochromic-lens


## References

1. Freebase Data Dumps. 2013
2. Quora