Night blindness also known as Nyctalopia is not a diagnosis, but rather a symptom of an underlying disorder. People with night blindness (also called impaired dark adaptation) see poorly in the darkness but see normally when adequate amounts of light are present. The condition does not actually involve true blindness, even at night. Recovery is fairly rapid when intake is reduced. Night Blindness is commoner than one can expect it to be.
There are many causes of Night Blindness. Night blindness can be linked to a variety of conditions caused by impaired liver function, which in turn reduces vitamin A in the body. Vitamin A deficiency is a common cause for night blindness. Some people are just born with it. Many people who are alcoholics or drink a lot may also get Night Blindness because drinking can damage your liver, which makes it easier to pick up an infection of any kind.
Symptoms include difficulty seeing when driving in the evening or at night, poor vision in reduced light. You may have a feeling that your eyes take longer to "adjust" to seeing in the dark. Initially there is slight difficulty in seeing in dim light later this progresses. The field of vision becomes narrow then later limitations in day vision. If no medication is taken blindness can occur. Toxic symptoms can occur with a large intake of Vitamin A. This is called Hypervitaminosis A, which leads to loss of appetite, a dry, itchy skin often with peeling, intense headaches and an enlarger liver.
Night Blindness starts at an early age, around 15 years and progresses into adulthood. Typical sufferers of Night Blindness are the elderly, teenagers and alcoholics. Many younger kids maybe born with night blindness it may also be an indicator of Retinitis...