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.