Chapter 7 Eye Terms

conjunctiva

mucous membrane that lines the eyelids and outer surface of the eyeball

orbit

bony cavity of the skull that encases the eye

lacrimal glands

glands that secrete tears

tarsal glands; meibomian glands

oil glands along the edges of the eyelids that lubricate the eye

aqueous humor

watery fluid that fills the anterior chamber of the eye between the lens and the cornea

cornea

transparent outer covering of the anterior portion of the eye

iris

colored muscular part of the eye located behind (posterior to) the cornea that allows light to pass through

sclera

tough fibrous outer layer of the eye (white) that extends from the cornea to the optic nerve

choroid

middle layer of the eye that contains blood vessels

lens

transparent structure behind the pupil that bends and focuses light rays

pupil

opening in the middle of the iris through which light passes

vitreous humor

jelly-like fluid that fills the posterior chamber of the eye between the lens and the retina

fundus

posterior portion of the interior of the eyeball, visible through the ophthalmoscope

optic nerve (CN 1)

cranial nerve I that carries impulses from the retina to the brain to provide the sense of sight

retina

innermost layer of the eye that contains visual receptors (rods and cones)

accommodation

ability of the eye to adjust focus on near objects

binocular

pertaining to both eyes

intraocular

within or inside the eye

amblyopia

poor vision, usually in only one eye, caused by abnormal development of the visual areas; also known as “lazy eye”

astigmatism

distorted, blurry vision caused by abnormal curvature of the cornea and/or lens

blepharitis

inflammation of the eyelid

blepharoptosis

drooping of the eyelids; also shortened to ptosis

blepharospasm

contraction of the muscles surrounding the eye, causing uncontrolled blinking

cataract

clouding of the lends of the eye, causing poor vision

chalazion; meibomian cyst

inflammation of the eyelid from a blocked tarsal gland

color blindness

deficiency in distinguishing some colors

conjunctivitis

highly contagious inflammation of the conjunctiva; commonly known as pinkeye

dacryolith

stone in the lacrimal sac or lacrimal ducts

dacryorrhea

excessive discharge of tears

detached retina

separation of the retina from the chord in the back of the eye; can be caused by injury, tumor, or hemorrhage

diabetic retinopathy

degenerative changes of the retina caused by diabetes mellitus; may lead to blindness

diplopia

double vision

exophthalmos/mus

abnormal protrusion of one or both eyeballs

glaucoma

group of diseases of the eye characterized by increased intraocular pressure that damages the optic nerve

hordeolum

infection of an oil gland if the eyelid; commonly called a sty

hyperopia

far-sightedness

keratomalacia

softening of the cornea, usually associated with severe vitamin A deficiency

macular degeneration

deterioration of the macula causing impaired central vision; most commonly related to advancing age

myopia

near-sightedness

nyctalopia

poor vision in reduced light or at night; commonly called night blindness

nystagmus

involuntary rhythmic movement of the eye

ophthalmia

condition of the eye characterized by severe conjunctivitis

ophthalmopathy

any disease of the eyes

photophobia

extreme sensitivity to light

presbyopia

impaired vision caused by old age

pterygium

growth of conjunctival tissue over the cornea; usually associated with prolonged exposure to ultraviolet light

retinal tear

small retina detachment that allows vitreous fluid to seep under the retina

retinitis pigmentosa

hereditary progressive deterioration of the retina causing nyctalopia and impaired vision

strabismus

abnormal alignment of the eyes caused by intraocular muscle imbalance; also called crossed eyes

xerophthalmia

excessive dryness of the conjunctiva and cornea, usually associated with vitamin A deficiency; dry eyes

extraocular movement (EOM)

movement of the upper eyelids and eyeballs through use of the extraocular muscles; assessed during clinical examination to screen for eye movement disorders

fluorescein angiography

visualization and photographic recording of the flow of an orange fluorescent dye through the blood vessels of the eye

keratometer

instrument used for measuring the curvature of the cornea

refraction

test using a manual refractor to determine an exact prescription for corrective lenses

Snellen chart

chart containing letters that is used to test visual sharpness (acuity)

visual acuity (VA) testing

testing for the sharpness (clarity) of distant vision, usually with a Snellen chart; normal visual acuity is 20/20

visual field (VF) testing

assessment of the range (area) visible to one eye without movement

enucleation

removal of an eyeball

intraocular lens (IOL) implant

implantation of an artificial lens to replace a defective natural lens

laser-assisted in situ keratomileusis (LASIK)

procedure that uses a laser to create a corneal flap and reshape the corneal tissue; used to correct vision problems such as myopia, hyperopia, and astigmatism

phacoemulsification

use of ultrasound to shatter and break up a cataract followed by aspiration and removal

photo refractive keratectomy (PRK)

procedure using a laser to reshape the cornea to correct vision

retinal photocoagulation

repair of a retinal detachment or tear by using a laser beam to coagulate the tissues to allow a seal to form

scleral buckling

repair of a retinal detachment by attaching a band (buckle) around the sclera to keep the retina from pulling away

trabeculectomy

surgical procedure to create a drain to reduce pressure within the eye

corticosteroid

drug that reduces inflammation; used to treat swelling and itching of the eye

hypotonic

drug used to relieve dry irritated eyes

miotic

drug used to constrict the pupil

mydriatic

drug used to dilate the pupil

prostaglandin

drug that relaxes muscles in the eye’s interior to allow better outflow of fluids

optician

one who fills prescriptions for corrective lenses

ophthalmology

medical speciality concerned with the study of the eye, its diseases, and refractive errors