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The WHO estimated in 1995 that 13.8 million children had some degree of visual loss related to VAD. [10] Night blindness and its worsened condition, xerophthalmia, are markers of Vitamin A deficiency; collections of keratin in the conjunctiva, known as Bitot's spots, and ulceration and necrosis of cornea keratomalacia can be seen.
Nyctalopia (/ ˌ n ɪ k t ə ˈ l oʊ p i ə /; from Ancient Greek νύκτ-(núkt-) 'night' ἀλαός (alaós) 'blind, invisible' and ὄψ (óps) 'eye'), [1] also called night-blindness, is a condition making it difficult or impossible to see in relatively low light. It is a symptom of several eye diseases.
Childhood blindness is an important contribution to the national prevalence of the disability of blindness. [3] Blindness in children can be defined as a visual acuity of <3/60 in the eye with better vision of a child under 16 years of age. [4]
Congenital blindness is a hereditary disease and can be treated by gene therapy. Visual loss in children or infants can occur either at the prenatal stage (during the time of conception or intrauterine period) or postnatal stage (immediately after birth). [3] There are multiple possible causes of congenital blindness.
The condition is not congenital and develops over the course of a few months as the lacrimal glands fail to produce tears. Other conditions involved in the progression already stated include the appearance of Bitot's spots, which are clumps of keratin debris that build up inside the conjunctiva and night blindness, which precedes corneal ulceration and total blindness.
Retinitis pigmentosa is the leading cause of inherited blindness, [51] with approximately 1/4,000 individuals experiencing the non-syndromic form of their disease within their lifetime. [52] It is estimated that 1.5 million people worldwide are currently affected.
Night blindness, on the other hand, which is also referred to as nyctalopia, is a condition in which someone has extreme difficulty or loses the ability to see in the dark or in dimly lit areas ...
Approximately 250,000 to 500,000 malnourished children in the developing world go blind each year from a deficiency of vitamin A. [49] Vitamin A deficiency in expecting mothers increases the mortality rate of children shortly after childbirth. [50] Night blindness is one of the first signs of vitamin A deficiency. Vitamin A deficiency ...