Eyes_Lab Manual Vocab Flashcards
Accommodation
Accommodation: adjustment of the eye for various distances through modification of the lens curvature.
Amsler grid
Amsler grid: a set of charts with various geometric shapes in black and white, used for detecting defects of the central visual field.
Anisocoria
Anisocoria: inequality of the diameter of the pupils; may be normal or congenital. Often normal if inequality is within 1mm.
Aphakia
Aphakia: a condition in which part or all of the crystalline lens of the eye is absent, usually because of surgical removal for the treatment of cataracts.
Aqueous humor
Aqueous humor: the watery transparent liquid containing trace albumin and small amount of salts produced by the iris, ciliary body, and cornea. It circulates through the anterior and posterior chambers of the eye.
Astigmatism
Astigmatism: an 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
Cataracts: opacity of the lens; most commonly resulting from denaturation of the lens protein caused by aging.
Chalazion
Chalazion: small, hard tumor analogous to sebaceous cyst developing on the eye lids, formed by the distention of a meibomian gland with secretion.
Choroid
Choroid: the middle vascular tunic of the eye lying between the retina and the sclera. Dark brown vascular coat of the eye between the sclera and retina, extending from ora serrata to optic nerve. Consists of blood vessels united by connective tissue containing pigmented cells and is made up of five layers.
Ciliary body
Ciliary body: the 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
Cones: the photosensitive, outward-directed, conical process of a 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 toward the periphery of the retina.
Confrontation
Confrontation: a test for estimating peripheral vision.
Conjunctiva
Conjunctiva: the mucous membrane investing the anterior surface of the eyeball and the posterior surface of the lids.
Conjunctivitis
Conjunctivitis: inflammation of the conjunctiva caused by infectious agents or by allergies; commonly called pinkeye.
Cornea
Cornea: the clear, transparent anterior portion of the fibrous coat of the eye comprising about one sixth of its surface. It is the chief refractory structure of the eye.
Corneal arcus
Corneal arcus: opaque white ring about corneal periphery, seen in many individuals older than 60 years of age. This is due to deposit of lipids in the cornea or to hyaline degeneration. May indicate a lipid disorder, most commonly type II hyperlipidemia if present before the 40 years of age (if seen in younger people, it is called arcus juvenilis).
Cotton wool spot
Cotton wool spot: an ill-defined yellow areas due to infarction of the nerve layer of the retina.
Depth perception
Depth perception: perception of spatial relationships; three dimensional perception. The visual ability to judge depth or distance.
Diabetic retinopathy (background)
Diabetic retinopathy (background): a condition characterized by dot hemorrhages or microaneurysms and the presence of hard and soft exudates.
Diabetic retinopathy (proliferative)
Diabetic retinopathy (proliferative): a condition characterized by development of new vessels as a result of anoxic stimulation; vessels grow out of the retina toward the vitreous humor.
Diopter
Diopter: refractive power of the lens with focal distance of 1 meter, used as unit of measurement in refraction.
Diplopia
Diplopia: the condition in which a single object is perceived as two objects (double vision).
Drusen
Drusen: tiny yellow or white deposits in the retina of the eye or on the optic nerve head.
Ectropion
Ectropion: eversion (outward rolling) of an edge or margin; as the edge of the eyelid.
Episcleritis
Episcleritis: inflammation of the superficial layers of the sclera located in front of the insertion of the rectus muscle.
Entropion
Entropion: inversion (inward rolling) of an edge or margin; especially the margin of the lower eyelid.
Exophthalmos
Exophthalmos: an increase in the volume of the orbital content, causing a protrusion of the globes forward. It may be bilateral or unilateral. The most common cause of bilateral is Graves’ disease (thyroid disease), but when unilateral protrusion is noted a retro-orbital tumor must be suspected.
Farsightedness
Farsightedness: an error of refraction in which, with accommodation completely relaxed, parallel rays come to focus behind the retina.
Glaucoma
Glaucoma: a disease of the optic nerve wherein the nerve cells die, producing increased cupping appearance of the optic nerve. An abnormal condition of elevated pressure within an eye resulting from obstruction of the outflow of aqueous humor. Produces defects in the visual field and may result in blindness.
Hemianopia
Hemianopia: blindness for half the field of vision in one or both eyes.
Hordeolum
Hordeolum (sty): a suppurative inflammation of a sebaceous gland of the eyelid.
Hyperopia
Hyperopia (farsightedness): a refractive error in which light rays entering the eye are focused behind the retina.
Hypertelorism
Hypertelorism: eyes spaced widely apart.
Hyphema
Hyphema: blood in the anterior chamber of the eye in front of the iris.
Iris
Iris: the colored contractile membrane suspended between the lens and cornea in the aqueous humor of the eye, separating the anterior and posterior chambers of the eyeball and perforated in the center by the pupil. By contraction and dilatation it regulates the entrance of light.
Iritis
Iritis: inflammation of the iris.
Legal blindness
Legal blindness: in the United States, a person is usually considered legally blind when vision in the better eye, corrected by glasses, is 20/200 or less, or in the case of a constricted field of vision: 20 degrees or less in the better eye.
Macula
Macula (also known as fovea): site of central vision.
Mydriasis
Mydriasis: pupillary dilation.
Miosis
Miosis: abnormal contraction of pupils.
Myopia
Myopia (nearsightedness): a condition resulting from a refractive error in which light rays entering the eye are brought into focus in front of the retina.
Night blindness
Night blindness: decreased ability to see in reduced illumination. Seen in patients with impaired rod function; often associated with a deficiency of vitamin A.
Nystagmus
Nystagmus: involuntary rhythmic movements of the eyes; the oscillations may be horizontal, vertical, rotary, or mixed.
Papilledema
Papilledema: edema of the optic disc resulting in loss of definition of the disc margin; the cause often is increased intracranial pressure.
Peripheral vision
Peripheral vision: vision resulting from retinal stimulation beyond the macula.
Pinguecula
Pinguecula: a harmless yellowish triangular nodule in the bulbar conjunctiva on either side of the iris that stops at the limbus.
Presbyopia
Presbyopia: hyperopia (farsightedness) and impaired near vision from loss of lens elasticity, generally developing during middle age.
Pterygium
Pterygium: a triangular (patch like) thickening of the bulbar conjunctiva that grows slowly to the outer surface of the cornea, usually from the nasal side, and may cover a portion of the cornea.
Ptosis
Ptosis: the drooping of one or both upper eyelids.
Punctum
Punctum: the tiny aperture (opening) in the margin of each eyelid that opens to the lacrimal duct.
Red reflex
Red reflex: a response caused by light illuminating the retina.
