How long does it take for eyes to adjust from bright light darkness?

It takes approximately 20-30 minutes for the human eye to fully adjust from bright light to darkness. The dark adaptation process is gradual and is influenced by several factors, including the levels of brightness and the individual's overall eye health.

During this period, the eye undergoes both physical and chemical changes to enhance its sensitivity to low-light conditions. Initially, the pupil dilates (widens) to allow more light to enter the eye. The retina's cone cells, responsible for sharp daytime vision, gradually decrease their activity, and rod cells begin to take over in dimly lit environments.

Rod cells play a vital role in night vision as they are incredibly sensitive to small amounts of light and are primarily responsible for detecting shapes and movements in dark conditions. The increase in rhodopsin (a light-sensitive pigment within rod cells) and changes in the photoreceptor cells increase the overall sensitivity of the retina to low light, thereby improving night vision.