med term chapter 15

accommodation

A process of having to adapt the lens of the eye. Also a medical procedure to test the flexibility of the lens on near and distance vision.

macular degeneration

A process of reversal of creation (progressive loss of vision) pertaining to the macula.

enucleation

A process surgical procedure to remove the main part of the eyeball.

fluorescein angiogram

A record or picture (x-ray image) of the blood vessels of the retina.

visual cortex

Area in each occipital lobe. It merges images from both eyes to create a single image.

optic chiasm

Area in the brain where parts of the right and left optic nerves cross to merge the visual fields from both eyes.

myasthenia gravis

Autoimmune disorder with abnormal and rapid fatigue of the muscles, particularly the muscles of the face and eyelids.

optic disk

Bright yellow-white area on the retina where the optic nerve and retinal arteries enter the posterior cavity. Also known as the blind spot.

lens capsule

Clear membrane that surrounds the lens.

lens

Clear, flexible disk behind the pupil. It changes shapeto focus light rays on the retina.

cataract

Clouding of the lens that obscures vision.

photophobia

Condition in which light causes fear or avoidance.

hyperopia

Condition of (at a distance that is) more than normal vision (but vision of near objects is blurry). Also known as farsightedness.

esotropia

Condition of (one or both eyes) inward turning. Also known as cross-eye.

exotropia

Condition of (one or both eyes) outward turning. Also known as wall-eye. play

amblyopia

Condition of dimness because of suppression of vision in one eye.

diplopia

Condition of double vision.

xerophthalmia

Condition of dry eyes. Also known as dry eyes syndrome.

retrolental fibroplasia

Condition of fiber growth pertaining to behind the lens of the eye (actually in the retina). Another name for retinopathy of prematurity.

entropion

Condition of inward turning of the lower eyelid.

myopia

Condition of normal near vision (but vision of far objects is blurry). Also known as nearsightedness.

presbyopia

Condition of old age vision. Loss of flexibility of the lens with blurry near vision and loss of accommodation.

ectropion

Condition of outward turning of the lower eyelid.

visual acuity

Condition of sharpness of sight or vision.

corneal abrasion

Condition of the superficial layer of the cornea being scraped off.

optic nerve

Cranial nerve II. A sensory nerve that brings sensory information from the retina of the eyes to the brain.

oculomotor nerve

Cranial nerve III. Motor nerve that sends motor commands to move the eyeball, eyelid, and pupil.

trochlear nerve

Cranial nerve IV. Motor nerve that sends motor commands to move the eyeball

abducens nerve

Cranial nerve VI. Motor nerve that sends motor commands for movement of the eyeball.

macula

Dark yellow-orange area in the retina. It contains the fovea.

strabismus

Deviation of one or both eyes medially or laterally. Category that includes esotropia and exotropia.

astigmatism

Disease from a specific cause of the cornea being without a point of focus. The surface of the cornea is curved more steeply on one side than on the other, so there is no single point of focus.

diabetic retinopathy

Disease of the retina of the eye caused by high levels of glucose and ketones from uncontrolled diabetes mellitus.

mydriatic drug

Drug pertaining to a process of widening (dilating) the pupils for an internal examination.

nasolacrimal duct

Duct that carries tears from the lacrimal sac to the inside of the nose.

lacrimal gland

Gland that produces tears.

retinitis pigmentosa

Hereditary condition of the retina with loss of color vision and central or peripheral vision.

conjunctivitis

Inflammation or infection of the conjunctiva

blepharitis

Inflammation or infection of the eyelid.

ophthalmoscope

Instrument used to examine the interior of the eye using a light and changeable lenses of different strengths.

nystagmus

Involuntary rhythmic motions of the eye.

inferior rectus muscle

Muscle that is straight (rectus) and moves the eye inferiorly.

lateral rectus muscle

Muscle that is straight (rectus) and moves the eye laterally.

medial rectus muscle

Muscle that is straight (rectus) and moves the eye medially.

superior rectus muscle

Muscle that is straight (rectus) and moves the eye superiorly.

superior oblique muscle

Muscle that moves the eye inferiorly and medially.

inferior oblique muscle

Muscle the moves the eye superiorly and laterally.

posterior chamber

Narrow space posterior to the iris. Aqueous humor circulates through it

ophthalmologist

One who specializes in the eye and the study of it.

optometrist

One who specializes in vision measurement.

ciliary body

Pertaining to a body that has hairlike structures (suspensory ligaments). It is an extension of the choroid. It also produces aqueous humor.

vitreous humor

Pertaining to a transparent substance. It fills the posterior cavity.

aqueous humor

Pertaining to a watery substance produced by the ciliary body. It circulates through the posterior and anterior chambers and takes nutrients and oxygen to the cornea and lens.

ulcerative keratitis

Pertaining to an ulcer due to inflammation or infection of the cornea

extraocular muscle

Pertaining to six muscles on the outside of the eye that control the eye movements.

pupillary

Pertaining to the pupil.

intraocular

Pertaining to within the eye.

hordeolum

Pimple containing pus on the eyelid. Also known as a stye.

tonometry

Process of measuring intraocular pressure to diagnose glaucoma.

phorometry

Process of measuring to correct the vision by using a range of lenses of different strengths.

miosis

Process of narrowing of the diameter of the pupil.

ultrasonography

Process of recording ultra high-frequency sound waves to make an image.

blepharoplasty

Process of reshaping the eyelids by surgery.

gonioscopy

Process of using an instrument (a slit lamp) to examine the angle and the trabecular meshwork

funduscopy

Process of using an instrument to examine the fundus (part farthest from the opening or pupil).

mydriasis

Process of widening of the pupil.

exophthalmos

Pronounced outward bulging of the eyes with a startled, staring expression. Caused by hyperthyroidism.

caruncle

Red, triangular tissue at the medial corner of the eye.

pupil

Round opening in the iris that allows light rays to enter the internal eye.

retinal detachment

Separation of the retina from the choroid layer beneath it.

optician

Skilled professional or expert in vision who grinds lenses to specifications in a written prescription.

corneal ulcer

Sloughing off of part of the cornea because of chronic infection or abrasion.

fovea

Small depression in the center of the macula. It is the area of sharpest vision.

anterior chamber

Small space between the cornea and the iris. Aqueous humor circulates through it.

lacrimal sac

Small structure that collects tears as they drain from the medial aspect of the eye.

choroid

Spongy membrane of blood vessels that is the middle layer between the sclera and the retina.

convergence

State of both eyes coming together as an object moves closer.

blepharoptosis

State of prolapse or drooping of the eyelid.

jaundice

State of yellow discoloration of the skin and whites of the eyes.

laser photocoagulation

Surgery on the retina using light from a laser to cause clotting of bleeding or leaking blood vessels.

corneal transplatation

Surgical procedure to move a donor cornea to another place as the patient's new cornea.

extracapsular cataract extraction

Surgical procedure to remove a lens because of a cataract. The central part of the lens is pulled out but the capsule is left intact.

papilledema

Swelling (edema) and inflamation of an elevated structure (the optic disk). Also known as a choked disk.

retina

Thin layer of tissue lining the posterior cavity. Also known as the fundus.

cornea

Transparent layer over the anterior part of the eye. It is a continuation of the white sclera.

cryotheraphy

Treatment that uses cold to freeze tissues to fix a detached retina.

retinoblastoma

Tumor (cancer) of the retina composed of embryonic cells.

glaucoma

Tumor of silver gray. (This word definition was based on an old description that confused glaucoma with a cataract.) Glaucoma causes increased intraocular pressure because aqueous humor cannot circulate freely.

scleral icterus

Yellow coloration of the sclerae from jaundice.