Errors of Refraction (Ch 17)

Astigmatism

Defective curvature of the cornea or lens of the eye

Hyperopia (hypermetropia)

Farsightedness

myopia

Nearsightedness

Presbyopia

Impairment of vision as a result of old age

Cataract

Clouding of the lens, causing decreased vision

Chalazion

small, hard cystic mass (granuloma) on the eyelid

Diabetic retinopathy

Retinal effects of diabetes mellitus, including microaneurysms, hemorrhages, dilation of retinal veins, and neovascularization (new blood vessels form in the retina)

Glaucoma

Increased intraocular pressure results and damage to the retina and optic nerve with loss of vision

hordeolum (stye or sty)

Localized, purulent, inflammatory staphylococcal infection of a sebaceous oil-producing gland in the eyelid

Macular degeneration

Progressive damage to the macula of the retina

Nystagmus

Repetitive rhythmic movements of one or both eyes

Retinal detachment

Two layers of the retina separate from each other

Strabismus

Abnormal deviation of the eye