Amblyopia (lazy eye):
Condition in which the vision in one eye is reduced because the eye and brain are not working together. It is the most common cause of visual impairment in children.
Asthenopia:
Eye strain.
Blepharitis:
Inflammation of the margin of the eyelid.
Cardinal Fields of gaze test:
Assessment of the positions to which the eye may normally be moved by the extraocular muscles.
Cataract:
Opacity of the crystalline lens of the eye, which obstructs the passage of light.
Chalazion:
Cyst (meibomian gland lipogranuloma) in the eyelid resulting from inflammation of the meibomian gland.
Conjunctivitis:
Inflammation or infection of the transparent membrane (conjunctiva) that lines the eyelid and part of the eyeball.
Corneal light reflex test:
A clinical test that is used to screen for strabismus.
Cover test:
A clinical assessment that is used to test for the presence and degree of ocular deviation.
Exophthalmos:
Bulging of the eye anteriorly out of the orbit.
Floaters:
Translucent specks that drift across the visual field-, common in people older than 40 years of age and people who are nearsighted.
Glaucoma:
Disease in which the optic nerve is damaged, leading to progressive, irreversible loss of vision. It is often, but not always, associated with increased pressure of the eye.
Hordeolum:
Sty.
Hyperopia:
Farsightedness.
Jaeger test:
Acuity test for near vision.
Lacrimal apparatus:
Physiologic system containing the orbital structures for production and drainage: consists of the lacrimal gland and its excretory ducts, lacrimal canaliculi, lacrimal sac, nasolacrimal duct, and nerve supply.
Limbus:
Border between the cornea and sclera.
Macula:
Structure lateral to the optic disc, the area with the greatest concentration of cones.
Macular degeneration:
Disease that gradually causes loss of sharp central vision, needed for common daily tasks.
Myopia:
Nearsightedness.
Palpebral fissure:
Almond-shaped open space between the eyelids.
PERRLA:
Acronym that stands for pupils equal, round, and reactive to light and accommodation.
Presbyopia:
Considered a natural part of aging: a condition that results from loss of elasticity of the crystalline lens. As this happens, the ciliary muscles that bend and straighten the lens lose their power to accommodate.
Retinopathy:
Damage to retinal blood vessels. The two most common causes are diabetes and hypertension.
Snellen test:
Test using a Snellen chart to measure visual acuity.