Vision - night blindness

Nyctanopia; Nyctalopia; Night blindness

Night blindness is poor vision at night or in dim light.

External and internal eye anatomy

The cornea allows light to enter the eye. As light passes through the eye the iris changes shape by expanding and letting more light through or constricting and letting less light through to change pupil size. The lens then changes shape to allow the accurate focusing of light on the retina. Light excites photoreceptors that eventually, through a chemical process, transmit nerve signals through the optic nerve to the brain. The brain processes these nerve impulses into sight.



Home Care

When to Contact a Medical Professional

What to Expect at Your Office Visit