What is night blindness?
Night blindness is usually characterized by havingdifficulties seeing in poor light and being unable to see properly at night.The medical term for night blindness is nyctalopia. Nyctalopia is an eyecondition in which a person cannot see properly at night or in any situation involvingpoor light conditions. Night blindness occurs due to the disorder of the rodcells which are located in the outer retina area. These cells are responsiblefor proper vision in poorly illuminated spaces. The condition may occur due tomalnutrition a traumatic injury to the eyes or some other eye problem. In somecases night blindness can occur due to the genetic predispositions.
There are plenty of symptoms that can be associated withnight blindness, but the condition is usually characterized by havingdifficulties seeing at night, in poor light and in darkness during daytime.Other common symptoms of night blindness also include blurred vision and dryeyes. Another symptom is the significant reduction of the contrast vision whichcan be noted most easily by being unable to see pedestrians in poorly litstreets. Persons who suffer from night blindness cannot read or watchtelevision for extended periods of time because their eyes get tired easily.These persons also have problems getting adjusted when coming from brightly litareas towards dimly lit areas. People who suffer from night blindness usuallyhave troubles driving at night and they often require extra light when reading.As a result of impaired vision a person may stumble on the pavement or thestairs. Sometimes laser vision surgeries may result in night blindness as aside effect of the procedure.
The main cause of night blindness is the decreased lightresponse of the rod cells located in the retina. The loss of response decreasesgradually and the condition is medically referred to as progressive nyctalopia.Sometimes the daytime vision can be affected as well because the optic nervebecomes pale white. If the night blindness is genetic the problem with thefunctionality of the retina rod cells will be present since birth. In cases of genetic night blindness thecondition usually does not get worse and is known as X linked congenitalstationary blindness. Night blindness can also be cause by vitamin A deficiencybecause it makes the eyes dry and sometimes can even lead to nyctalopia. Nightblindness can also be caused by loss of side vision, cataracts andnearsightedness. There are some cases of night blindness caused by constrictionof the pupil due to the treatment with glaucoma medications.
Night blindness can be treated by removing the cataracts ifthey are the cause of the condition. Increase of vitamin A ingestion by eatingcertain types of food and the intake of supplements are usually a part of thetreatment. One should stop taking any glaucoma medications and visit anophthalmologist to get the eyes tested.