Night blindness, also called nyctalopia, is a symptom of several different diseases or conditions.
nyctalopia
nyctalopia
nyctalopia
Night blindness, which is called nyctalopia, may be caused by an injury to the eye or be inborn. It is more common in men than women and can be treated in early cases by vitamin A.
nyctalopia
night blindness
Night blindness, also known as nyctalopia, is a difficulty or inability to see in low light. This can be caused by a Vitamin A deficiency.
Nyctalopia (night blindness) is one of the first signs of deficiency of Vitamin A. moreover, deficiency of this vitamin can also produce Xerophthalmia (a medical condition in which the eye fails to produce tears), keratomalacia (an eye disorder resulting when the cornea becomes totally opaque and occurs blindness), and complete blindness since Vitamin A has a major role in phototransduction.
Beriberi is caused by thiamine (vitamin B1) deficiency Goitre can be caused by iodine deficiency - although there are other potential causes. Scurvy is caused by vitamin C deficiency Night blindness (Nyctalopia) can have many different causes - but one cause is vitamin A deficiency.
Ocular is the medical term meaning pertaining to vision. For instance, the extraocular movements (abbreviated EOMs) are the muscle movements that the examiner checks when they ask you to follow their finger while you keep your head still.
People who suffer from hemeralopia actually see better in faint or dim light than they do in bright light. That's why another term for the condition is "day blindness." It's the opposite of night blindness. With hemeralopia, seeing in bright light (or even normal sunlight) can be painful and/or cloudy. The most effective means of fighting hemeralopia depend on what's causing it, and it can be caused by a variety of factors. Some people with uveitis suffer from hemeralopia, as do some people with complications from laser eye surgery. Some medications can cause light sensitivity as a side effect. Sunglasses work for some people but not for others. The best course of action is to see a qualified eye doctor. A clarification -- hemeralopia literally means "day blindness"; nyctalopia is the word for "night blindness". The two words have fallen more or less out of use because they're confusing. If you run an internet search on hemeralopia, for instance, you'll find a lot of sites where it's defined as the inability to see clearly in bright light -- but you'll also find sites where it's defined as the inability to see clearly EXCEPT IN bright light. The same thing happens with nyctalopia and darkness. So it seems that most people just use the terms "day blindness" (trouble seeing in bright light) and "night blindness" (trouble seeing in darkness).
People most likely to have vitamin A deficiency are those with diseases (such as digestive disorders) or very poor diets Vitamin A is essential for producing tears and keeping the surface of the eye moist and free of infection. Inadequate Vitamin A levels will also damage the clear cornea. Nearly everyone knows that carrots (loaded with Vitamin A) are healthy for the retinal cells - the photoreceptors. Poor vision in dim light (nyctalopia) is one of the earliest symptoms of Vitamin A deficiency, hypovitaminosis A. Beta-carotene supplements may help people with specific health problems. Supplements might be used in someone with a clear vitamin A deficiency. Itmight help those with the genetic condition erythropoietic protoporphyria (EPP.)