Understanding Nyctalopia
Understanding Nyctalopia

Understanding Nyctalopia

Nyctalopia, also known as night-blindness, is an impairment that affects your ability to see at night. It could be due to a dietary imbalance, an eye condition or a chronic eye disease.


Night vision is different from daytime vision. At night, the ability to perceive colours is reduced to black, white and greys. Your central fields of vision are reduced meaning you will see moving objects clearer than static objects.


Symptoms of nyctalopia include; weak vision in dim light, difficulty seeing when driving at night and slow reaction time between bright and dim light conditions. Driving at night can be particularly challenging due to the intermittent presence of headlights and streetlights on the road.


While a condition in its own right, night blindness may be the result of a related eye problem, listed below.

Astigmatism - With astigmatism, when lighting dims, your pupils dilate to let in more light creating more blur than you would in daylight.

Diabetes - Poor night vision can be an early sign of diabetes. High blood sugar is harmful to the blood vessels and nerves in the eye. A symptom of diabetes is retinopathy, where the back of the eye is gradually damaged. As a result, adjustment to light, such as coming indoors from bright light outside, is slowed.

Cataracts - With cataracts, you'll notice that oncoming headlights cause more glare than before as you'll be more sensitive to light.

Retinitis Pigmentosa - A group of inherited vision disorders that leads to the progressive degeneration of the retina. Deteriorating night vision is often the earliest symptom. Over time, the peripheral (side) vision gradually decreases.


Your optician will be able to diagnose night blindness through a full eye examination and will determine the cause. If it is due to your refractive error, myopia or astigmatism, they will prescribe you with new spectacle lenses. If you have a cataract you will be referred to have it removed to improve your night vision. Your optician may have to carry out further necessary examinations to determine the cause and will be able to look into the correct avenues to improve it. If you're suffering from night blindness symptoms contact your optician for further advice.