Definition of photochromic in English:



  • (of a substance) undergoing a reversible change in colour or shade when exposed to light of a particular frequency or intensity.

    ‘photochromic sunglasses’
    • ‘Therefore, we have attempted to create a simple, reversible photochromic metal-ion chelator that can be analyzed quantitatively.’
    • ‘When a photochromic material is exposed to light, the light absorption properties of the material change.’
    • ‘Also, photochromic substances can be restored to their original state after being in the dark for a period of time.’
    • ‘With its photochemical cycle, bR represents a reversible photochromic system in addition to its charge translocation property.’
    • ‘This reversible deprotonation and reprotonation causes the distinguished visible and fully reversible photochromic shift from purple to yellow.’


1950s: from photo- ‘relating to light’ + Greek khrōma ‘colour’ + -ic.