Eyes 1&2 Flashcards
Accommodation
Adjustment of the eye for various distances through modification of the lens curvature.
Amsler Grid
A set of charts with various geometric shapes in black and white, used for detecting defects on the central visual field.
Anisocoria
Inequality of the diameter of the pupils; may be normal or congenital. Often normal if inequality is within 1 mm.
Aphakia
Condition in which part or all of the crystalline lens of the eye is absent, usually due to surgical removal for cataract treatment.
Aqueous Humor
Watery transparent liquid containing trace albumin and small amounts of salts produced by the iris, ciliary body, and cornea. Circulates through the anterior and posterior chambers of the eye.
Astigmatism
Abnormal condition in which the light rays cannot be focused clearly in a point on the retina because of an irregular curvature of the cornea or lens.
Cataracts
Opacity of the lens; most commonly resulting from denaturation of the lens protein caused by aging.
Chalazion
Small, hard tumor analogous to sebaceous cyst developing on the eye lids, formed by the distention of a meibomian gland with secretion.
Choriod
Middle vascular tunic of eye lying between the retina and the sclera. Dark brown vascular coat of the eye between the sclera and retina, extending from ora serrate to optic nerve. Consists of blood vessels united by connective tissue containing pigmented cells and is made up of five layers.
Ciliary Body
Thickened part of the vascular tunic of the eye that joins the iris with the anterior portion of the choroid. Consist of three zones: ciliary disk, ciliary crown, and ciliary muscle.
Cones
Photosensitive, outward-directed, conical process of cone cell essential for sharp vision and color vision; cones are the only photoreceptor in the fovea centralis and become interspersed with increasing numbers of rods towards the periphery of the retina.
Confrontation
Test for estimating peripheral vision.
Conjunctiva
Mucous membrane investing the anterior surface of the eyeball and the posterior surface of the lids.
Conjunctivitis
Inflammation of the conjunctiva caused by infectious agents or by allergies; commonly called pinkeye.
Cornea
Clear, transparent anterior portion of the fibrous coat of the eye comprising about one sixth of its surface.
Corneal Arcus
Opaque white ring about the corneal periphery, seen in many individuals older than 60 years of age.
Cotton Wool Spot
Ill-defined yellow areas due to infarction of the nerve layer of the retina.
Depth Perception
Perception of spatial relationships; three dimensional perception. Visual ability to judge depth or distance.
Diabetic Retinopathy (Background)
Characterized by dot hemorrhages or microaneurysms and the presence of hard and soft exudates.
Diabetic Retinopathy (Proliferative)
Development of new vessels as a result of anoxic stimulation; vessels grow out of the retina toward the vitreous humor.
Diopter
Refractive power of the lens with focal distance of 1 meter, used as unit of measurement in refraction.
Diplopia
Condition in which a single object is perceived as two objects (double vision).
Drusen
Tiny yellow or white deposits in the retina of the eye or on the optic nerve head.
Ectropion
Eversion (outward rolling) of an edge or margin; as the edge of the eyelid.