Night blindness is an impaired dark adaptation.
It is the experience of reduced night vision. It typically causes people to not be able to see well in the darkness but be able to see without problem when it is not dark. This condition is not total blindness.
Even at nighttime, the eye is not “blind” but it occurs because the photoreceptor cells which are needed for dim light are not functioning correctly.
Symptoms:
– Weak vision in dim light.
– Difficulty seeing during night driving.
– Slow vision adaption between bright and dim light conditions
Causes:
Night blindness is due to a disorder of the cells in the retina that are responsible for vision in dim light. It has many causes. Some of them are:
– Short-sightedness.
– Glaucoma medications; that work by constricting the pupil.
– Cataracts
– Retinitis pigmentosa.
– Vitamin A deficiency.
Older people are at a greater risk of developing cataracts. They are more likely to suffer from night blindness than children or young people. Vitamin A deficiency also leads to night blindness. Vitamin A is also called retinol. It plays a role in transforming nerve impulses into images in the retina.
The retina is a light-sensitive area in the back of your eye. People who have diseases of the liver or pancreas sometimes cannot absorb large amounts of vitamin A. So, they are at greater risk to develop night blindness. Vitamin A is found in eggs, dairy, some fish and organ meats, etc.
The body makes vitamin A from carotene. Carotene is found in yellow-orange vegetables and fruits. Carotene can also be taken to reverse a deficiency but it is not as effective as taking vitamin A directly. This is because carotene is absorbed slowly by the body and slowly converted to vitamin A.
Preventive Measures
– Consume foods that contain vitamin A regularly.
– Dairy products such as milk, butter, ghee, etc. should be consumed regularly.
– Green vegetables and fruits should be consumed regularly.
– Organ meat and fish should be consumed regularly.
– Seek medical help immediately if it is suspected.
