A person is said to have night blindness if he/she has difficulty in seeing in low light conditions. This is more prominently felt in night time when lighting is dull. Many people tend to overlook the symptoms of night blindness at earlier stages and due to progressive degeneration the condition of blindness becomes severe with every passing day.
The causes can be both congenital as well as acquired i.e. developed over a period of time due to various causes and early detection makes it easy to manage the condition.
Causes of Night Blindness
Night blindness is usually the outcome of an unidentified vision disorder. The causes of the disorder are identified by the physician and treatment done accordingly.
Myopia or Short sightedness
Here there is a mismatch in focusing on the retina of the eye and hence the affected person will have a blurred vision of the distant objects especially in low lit conditions.
This is a condition where over a life time there is debris build-up on the lens of the eye, which turns opaque resulting in blurred vision under poor light conditions. Subsequently the lens becomes clouded and the vision is impaired.
Patients with diabetes tend to have night blindness over a period of time. High levels of sugar in the blood is damaging to the optic nerves of the eye as well as the retina, where the images are focussed in our eye. Prolonged diabetes lead to damage of the retina called retinopathy and finally cause blurred night vision or night blindness.
Vitamin A deficiency
One of the major causes of night blindness is deficiency of Vitamin A or Retinol. Vitamin A is found to protect the surface of the eye or cornea and hence is important for a good vision. In certain people the deficiency may also be the outcome of other ailments which makes it difficult to absorb the Vitamin from the gastrointestinal tract. Diseases such as Crohn’s disease, Celiac disease, Cystic fibrosis etc are also associated with Vitamin A deficiency.
In certain cases night blindness is also caused as a side effect of certain drugs. For example the drugs administered to cure Glaucoma are found to cause night blindness. Glaucoma is a condition in which there is a pressure build up on the nerves of the eye. The medication for this condition tends to constrict the pupils, the aperture of our eye lens, reducing the amount of light falling into the eyes, leading to blurred vision.
This is a genetic disorder of the eyes which is the most common cause for night blindness. The condition is characterised by blurred vision in dim lit conditions and mostly affects young people below the age of 30. Here the rod cells of the retina of the eye lose their ability to respond to light, which shows as night blindness in the initial stages progressing to loss of vision even in daytime.
Symptoms of Night Blindness
Look out for these symptoms and as in all cases earlier the detection, better would be the prospects of getting cured.
Difficulty in Adapting to Dim Light
The patient may have a blurred vision in a room with poor light or during night hours. Usually in normal cases persons will have difficulty to adapt to dim light while shifting their vision from a bright light. But persons afflicted by night blindness will take more time to adapt.
Unable to See Stars in Clear Sky
A person who is not able to have a clear vision of stars in a clear sky during night time is for sure suffering from night blindness. This is a clear deviation from normal vision and should not be over looked.
Persistent Dry Eyes
The cornea or the surface of the eye will dry out, devoid of lubrication causing dryness.
Being Clumsy In Low Light Condition
Are you being clumsy or knocking down things in front of you while in a poorly lit room? Then watch out! Many people tend to let these instances pass with excuses. If such instances happen often, then you might consult your physician for an eye check up.
Treatment for Night Blindness
Night blindness caused due to other factors except Retinitis pigmentosa and certain birth defects are treatable and the success of treatment depends on early detection and proper diagnosis.
Night blindness due to cataract is treated by performing cataract surgery and replacing the eye lens with an artificial intra ocular lens. This will ensure clear vision.
Diabetes and related night blindness is treated by keeping the blood sugar levels under control and also diet management. Advanced treatment methodology involves use of laser rays to correct the affected blood vessels of the eye. This is found to prevent further damage due to night blindness and preserve the vision.
Myopia related night blindness is treated using corrective lenses which ensure perfect vision.
Vitamin A deficiency and related blindness is corrected by intake of food sources rich in Vitamin A. This includes green leafy vegetables, carrots and brightly coloured vegetables. Animal sources of the Vitamin like meat, liver etc also serve the purpose. In ancient Egypt history, instances of curing night blindness by intake of liver can be found, which confirms the treatment methodology. Though night blindness due to retinitis pigmentosa is considered untreatable, certain research studies have shown that patients suffering from the ailment administered with a combination of Vitamin A and lutein, were found to have relatively slower vision impairment when compared to others.
Risk Factors Involved
These are factors that put one at an increased risk of getting affected by night blindness.
Old age people are at a higher risk of being affected by cataract and hence the chances of night blindness are higher.
Chance of getting night blindness due to retinitis pigmentosa is higher if there is occurrence of the disease in the family hereditary.
People who do not take Vitamin A rich diet like green leafy vegetables, eggs and whole milk products are at a risk of getting the disease. This is usually found in people of under developed countries due to malnutrition problems. People who are suffering from problems of the liver or gastro intestinal tract also are at a higher risk of being affected, as these conditions will reduce the absorption of Vitamin A into the blood.