scotopsin

biology

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July 13, 2026

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Scotopsin is a type of visual pigment found in the rod cells of vertebrate retinas, responsible for vision in dim light. Visual pigments are crucial for light reception in animals, converting light energy into electrical nerve signals.1

These pigments consist of a colored molecule called a chromophore, typically retinal (derived from vitamin A), and a protein called opsin. Scotopsins are specifically associated with low-light conditions, and when combined with retinal, they form rhodopsins (using retinal₁) or porphyropsins (using retinal₂). In contrast, photopsin pigments function in brighter light and are found in cone cells, differing from scotopsins mainly in their opsin component.1

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visual pigment
Scotopsin pigments are associated with vision in dim light and, in vertebrates, are found in the rod cells of the retina; the retinal₁ forms are called rhodopsins, and the retinal₂ forms porphyropsins. Photopsin pigments operate in brighter light than scotopsins and occur in the vertebrate…
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Scotopsin pigments are associated with vision in dim light and, in vertebrates, are found in the rod cells of the retina; the retinal₁ forms are called rhodopsins, and the retinal₂ forms porphyropsins. Photopsin pigments operate in brighter light than scotopsins and occur in the vertebrate…
Read More