Night blindness, or nyctalopia, is where the eye is unable to adapt to low-light conditions, such as at nighttime. Night blindness itself is not a condition but the result of an existing eye disorder.
When lighting is dim, the eye must adapt. Although night blindness adversely affects a person’s ability to see in dim light, it does not cause complete blindness. It may create problems seeing road signs while driving at night. It may also take longer time than usual for the eye to adapt when going from light to dark settings.
Night blindness is a symptom of some underlying conditions, which may have several causes. This article will discuss symptoms, potential causes, and treatments of night blindness.
Night blindness is a symptom of an underlying eye condition that results in vision impairment while in dim lighting.
For example, night blindness could prevent someone from being able to see stars at night, or obstacles in a dark room.
To identify night blindness, the American Academy of Ophthalmology suggests that people consider the following questions:
- Is moving around the house in dim light a challenge?
- Is driving at night increasingly difficult?
- Is it tricky to recognize faces in dim light?
- Does it take an abnormally long time to adjust to a light room after being in the dark?
- Does it take a long time to see in a darkened room after being in the light?
Other symptoms may also occur with night blindness. The nature of these symptoms will depend on the underlying cause but may include:
- headaches
- eye pain
- nausea
- vomiting
- blurry, or cloudy vision
- sensitivity to light
- difficulty seeing into the distance
Night blindness is the result of one of several conditions, many of which are treatable. Conditions can include:
Glaucoma
Glaucoma refers to a group of eye conditions where damage to the optic nerve, which connects the eye to the brain, causes pressure in the eye. This may impair vision, which can be permanent.
Cataracts
Cataracts occur when the lens of the eye becomes
Nearsightedness
People with
Vitamin A deficiency
Vitamin A, or retinol, is an
Retinitis pigmentosa
This is a group of rare
Treatment for night blindness will vary depending on the cause.
Treatment may include wearing specific types of glasses or contact lenses, which can help to support correct vision.
Wearing sunglasses can also protect the eye from ultraviolet light, which can cause further eye damage.
When the cause is a lack of vitamin A, treatment involves adding more Vitamin A to the diet. Good sources of vitamin A include:
- eggs
- fortified cereals
- fortified milk
- orange and yellow vegetables and fruits
- cod liver oil
- dark, leafy green vegetables
Eye surgery may be necessary in more severe cases. For example,
In some cases, night blindness may not be treatable. Retinitis pigmentosa currently has no
It may be helpful to take precautions to lower some of the risks that night blindness can cause. This might mean not driving at night, or avoiding having to navigate or move around in the dark wherever possible.
The outlook for night blindness depends on the cause.
The cause will have a range of straightforward treatments in many cases. This can be as simple as new glasses or contact lenses or adapting to a different diet. More severe cases may require surgery.
Effective treatment can significantly improve vision at night, as well as other symptoms of the underlying condition causing it.