Photopic vision

Photopic vision is the vision of the eye under well-lit conditions. In humans and many animals, photopic vision allows color perception, mediated by cone cells.

Photopic vision is the scientific term for human color vision under normal lighting conditions during the day.

The human eye uses three types of cones to sense light in three respective bands of color. The pigments of the cones have maximum absorption values at wavelengths of about 420 nm (blue), 534 nm (Bluish-Green), resp. 564 nm (Yellowish-Green). Their sensitivity ranges overlap to provide continuous (but not linear) vision throughout the visual spectrum. The maximum efficacy is 683 lumens/W at a wavelength of 555 nm (green).

Under low-light conditions, the human eye uses scotopic vision. Mesopic vision combines the photopic and scotopic vision types.