Search results
Results from the WOW.Com Content Network
Visual or vision impairment (VI or VIP) is the partial or total inability of visual perception.In the absence of treatment such as corrective eyewear, assistive devices, and medical treatment, visual impairment may cause the individual difficulties with normal daily tasks, including reading and walking. [6]
Vitamin A deficiency is a leading cause of preventable childhood blindness, particularly in developing countries. Vitamin A deficiency is defined as a serum (blood) concentration of less than 0.70 μmol/L while a severe deficiency is defined as less than 0.35 μmol/L, per the Centers of Disease Control National Health and Nutrition Examination ...
Floaters and spots are most commonly related to ageing. They are generally harmless and do not cause blindness [7] Eye flashing: characterised by bursts or streaks of light that appear in an individual's field of vision. As eye flashing may indicate impending retinal detachment, medical attention is required. [8]
There are many diseases known to cause ocular or visual changes. Diabetes , for example, is the leading cause of new cases of blindness in those aged 20–74, with ocular manifestations such as diabetic retinopathy and macular edema affecting up to 80% of those who have had the disease for 15 years or more.
Leber's congenital amaurosis (LCA) is a collection of inherited, degenerative eye disorders that can reduce the strength of visual clarity or sharpness in infants and can cause childhood blindness. [ 14 ] [ 15 ] These eye disorders are mostly autosomal recessive diseases, and diagnoses of LCA are linked to multiple gene variants, including the ...
Cortical blindness refers to any partial or complete visual deficit that is caused by damage to the visual cortex in the occipital lobe. Unilateral lesions can lead to homonymous hemianopias and scotomas. Bilateral lesions can cause complete cortical blindness and can sometimes be accompanied by a condition called Anton-Babinski syndrome. [26]
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.
Blue cone monochromacy (BCM) is an inherited eye disease that causes severe color blindness, poor visual acuity, nystagmus, hemeralopia, and photophobia due to the absence of functional red (L) and green (M) cone photoreceptor cells in the retina.