Question

tabularize the 2 main types of refraction abnomarlities of the human eye

Answer 1

Two types of abnormalities of human eye from some of the abnormalities are:

1) Near sightedness (Myopia) :  Near-sightedness, also known as short-sightedness and myopia, is an eye disorder where light focuses in front of, instead of on, the retina. This causes distant objects to be blurry while close objects appear normal

Symptoms: blurry vision, double vision, headache, eye strain.

Reason: This can arise from a cornea or crystalline lens with too much curvature (refractive myopia) or an eyeball that is too long (axial myopia).

Correction: Myopia can be corrected with a concave lens, which causes the divergence of light rays before they reach the cornea.

2) Farsightedness (Hypermetropia) :  Far-sightedness, also known as hypermetropia, is a condition of the eye in which light is focused behind, instead of on, the retina. This results in close objects appearing blurry, while far objects may appear normal.

Symptom: close objects appear blurry.

Reason : This can arise from a cornea or crystalline lens with not enough curvature (refractive hyperopia) or an eyeball that is too short (axial hyperopia).

Correction : This can be corrected with convex lenses, which cause light rays to converge prior to hitting the cornea.