noun see: optic Date: 1886 a red photosensitive pigment in the retinal rods of the eye of most vertebrates that is important in vision in dim light
RHODOPSIN
Meaning of RHODOPSIN in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012