A true night blindness is a very rare disease. Nevertheless, many people look bad, when it is dark. Mostly, but that is something other than a Hemeralopie, such as night-blindness is known in the technical jargon.
Thus, an impaired tear film, a Short – or far-sightedness, or a cloudiness of the lens is behind most cases of alleged impairment of vision. The decreased visual acuity is the rule, rather the manifestation of a different disease.
in fact, a decreased visual performance in the dark can also be a Symptom of a “real” night-blindness. As Hemeralopie a very rare network is referred to skin disease. Such is, see to be Concerned at night significantly worse or nothing at all – they are night blind.
debt can be a defect or a Vitamin A deficiency. Where night blindness occurs due to Vitamin A deficiency in Europe is extremely rare. Also night blindness can occur as a result of another disease such as Diabetes mellitus. Are affected, usually both eyes.
What we are, is perceived via the retina in the eye. There, the sensory cells that convert the perceived in the brain processable electrical pulse. This is sent via the optic nerve in our brain. In the eye there are two types of such receptors, the rods and the cones. The cones are for color vision, of the day responsible, the rods for Seeing in the twilight. These sticks do not work any more correctly, can not adapt to the man in the darkness, and is thus worse.
symptoms of night blindness
As the Name suggests, see to be Concerned, bad or anything in the dark. While others are still easily has a night blind feel the need to be groping.
The disease is very rare. Just one of an estimated 22’000 people is affected by hereditary night blindness. Depending on what causes the Hemeralopie, to the disease from birth or develops in the course of time.
About 5 percent of the population suffers from visual impairment to a Color. But what is actually a Color vision deficiency or color blindness?
diagnosis and treatment
Often may be sufficient in a conversation with the doctor to make the diagnosis of night blindness. In addition, the skilled person can measure with different devices, the vision of the eyes in the darkness. The diagnosis is made only once, has yet to be found out what type of night blindness is. To do this, the doctor examines the retina and is related receptors.
The treatment depends to a large extent, what is the cause of the visual impairment. The reason is a lack of Vitamin A, it can be well treated by Vitamin A is taken.
it is Difficult when the Hemeralopie is innate. In this case, no therapy can fix the causes. This means that hereditary night-blindness is incurable, and cannot be corrected by glasses.