Night Blindness (Nyctalopia)
What is night blindness?
Night blindness (nyctalopia) is your inability to see well at night or in poor light such as in a restaurant or movie theater. It is often associated with an inability to quickly adapt from a well-illuminated to a poorly illuminated environment. It is not a disease in itself, but rather a symptom of an underlying eye problem, usually a retina problem. It is common for people who are myopic to have some difficulties with night vision, but this is not due to retinal disease, but rather optical issues.
What happens to the eye in low or no light?
Your eyes are constantly adjusting to light. When you’re in low or no light, your pupils (that black circle in the center of your eyes) will get bigger (dilate) so that more light will enter your eye. That light is then received by the retina – tissue in the back of your eye that houses all of the rod and cone cells. Cone cells help you see color. Rod cells help you see in the dark. When those rods are not working well because of a disease, injury, or condition, you can’t see as well or at all in the dark.