Night blindness is a condition related to poor vision in darkness. It is not a disease, but a symptom of underlying disease. People suffering from this symptom see very well in the presence of adequate light. Everyone normally have momentary night blindness and it is normal, for example if you walk in from bright sunlight into a dark movie theater, it may be difficult to recognize the person who walked in with you for a moment. But soon the retina adjusts to the difference of light and you will be able to see the person beside you.
However, in some people suffering from night blindness, there is an impairment to dark adaptation in the retina, and it takes longer time or in some cases absolute lack of visual acuity to see the object in the dark. People with night blindness often have difficulty driving at night. If you have visual difficulty in seeing objects in darkness, you should first consult an ophthalmologist to rule out night blindness.
What Are The Causes Of Night Blindness?
Night blindness also called as nyctalopia is caused by defect in the rods and cones of the retina.
Night blindness due to acquired causes:
- Night blindness is one of the main symptoms of vitamin A deficiency. In vitamin A deficiency, the rods and cones in the retina do not grow normally, this causes disturbance in vision at night.
- Nearsightedness is another cause for night blindness, especially if the condition is not corrected with suitable glasses.
- Cataract may hamper the light to be focused on the retina. People suffering from cataract therefore complain of visual disturbance during nigh time.
- Drugs used in glaucoma can cause constriction in pupils and it may affect adaptation of light.
Congenital causes:
Night blindness can be congenital. It is believed to be one of the causes as X chromosome in some people having this symptom is found to be different than a normal individual.
Retinitis pigmentosa is a congenital eye disease where the retina is damaged since birth. Persons affected with this problem may have reduced night time vision. They may also suffer from central and peripheral vision disturbance.
Treatment Options For Night Blindness
Acquired night blindness is easy to treat and in majority of cases it can be completely cured once the underlying condition is resolved.
- Night blindness due to vitamin A deficiency is cured if the patient is given vitamin A supplements. However, it should be taken under physicians care as prolonged use of supplements can cause harmful effects on health. Together with supplements, patient should also eat foods containing vitamin A such as carrots, green leafy vegetables, fish and fish oil etc. Early recognition of vitamin A related night blindness and its effective treatment can reduce the risk of permanent night blindness.
- Night blindness due to cataract is completely cured after cataract surgery. If is it associated with nearsightedness, the symptom can be corrected by wearing proper glasses or lens.
- There is no definite cure for night blindness which is caused due to congenital problems like retinitis pigmentosa. Patient has to be frequently monitored by an ophthalmologist in such cases. He should try to avoid driving at night in order to reduce the risk of accidents.
- Bilberry from family of berries contains rich flavanoid which provides color. It contains pigments which are used in production of rods in the retina. They assist the eyes to improve night time vision. If taken in its early stage of night blindness, patient will find remarkable improvement in his poor night vision.