LIGHT AND DARK ADAPTATION

Light Adaptation
When exposed to sudden bright light, the eye adapts quickly—typically within about 10 seconds. However, prolonged exposure to bright light depletes a significant amount of the photochemicals in both rods and cones, reducing the eye's sensitivity to light. As a result, moving quickly from a bright outdoor environment into a dark room can cause a temporary, severe reduction in vision until the eyes have time to adapt to the darkness.

Dark Adaptation
If a person stays in darkness for an extended period, the opposite effect occurs: both the cones and rods gradually become highly sensitive to light. As a result, even very small amounts of light can stimulate the receptors. Dark adaptation takes approximately 7 minutes for the cones and about 30 minutes for the rods.

Eye adaptation to bright light → 10 seconds
Eye adaptation to darkness → 7 minutes for the cones, 30 minutes for the rods