otocleisis obstruction of the eustachian tube.
otology the study of ear diseases.
otoplasty plastic surgery on the ears, usually to repair cauliflower ears or lop ears.
otosclerosis a hereditary disorder characterized by the development of spongy bone over the stirrup, disrupting vibrations and causing progressive deafness. It is the most common form of conductive deafness.
pinna the external ear.
semicircular canal the labyrinth.
sensorineural deafness deafness caused by damage to the inner ear, to the auditory nerve or to the auditory cortex of the brain. Also known as nerve deafness.
stapes see stirrup.
stirrup one of the three tiny bones that transmit vibrations in the middle ear. Also known as stapes.
tinnitus ringing in the ears.
tympanic membrane the eardrum.
vertigo a sense that one is spinning or whirling around, a symptom of inner ear impairment.
eyes
aqueous humor the nutrient-rich fluid that fills the chamber between the cornea and the lens.
astigmatism distorted vision—usually affecting peripheral vision—due to abnormal curvature of the eye.
blind spot there are no photoreceptors where the optic nerve passes through the retina, thus the eye is literally blind to any images that fall there.
cataract a clouding of the lens, obscuring vision.
choroid membrane the layer of the eyeball containing blood vessels that nourish the eye.
color blindness an inability to identify color, usually red or green; it rarely affects females.
cones light-reactive nerve cells in the retina that are responsible for detecting color.
conjunctiva the mucous membrane lining the inner eyelid and the outer surface of the eyeball.
conjunctivitis inflammation of the conjunctiva.
cornea the transparent outer membrane of the eyeball.
crocodile tear syndrome shedding tears instead of salivating in anticipation of food, a rare disorder caused by the crossing of the nerves leading to and from the salivary and lacrimal glands, usually due to injury.
detached retina loss or deterioration of vision due to the retina becoming separated from the other layers of the eyeball.
diplopia seeing double.
dry eye syndrome inadequate functioning of the tear glands, producing dry eyes.
ectropion the turning-out of an eyelid so that it lies away from the eyeball.
entropion the turning-in of an eyelid, so that it scratches the eyeball.
epicanthus an extra skin fold covering the inner angle of the eye, normal in Asians and children with Down's syndrome.
esotropia a form of strabismus in which one eye is turned or crossed inward.
exophthalmos bulging of the eyeballs, caused by overactivity of the thyroid gland.
exotropia a form of strabismus in which one eye is turned or crossed outward.
floaters floating specks sometimes seen before the eyes; they're usually harmless, dead blood cells.
glaucoma increased intraocular pressure due to overproduction of aqueous humor or an obstruction of its normal flow; it causes visual defects or blindness.
grayout a blurring or temporary loss of vision in airplane pilots due to an oxygen deficiency.
helerochroma iridis the condition of having one blue eye and one brown eye, present in 2 out of every 1,000 people.
hyperopia farsightedness; the ability to see things far away but not close up.
keratitis acute or chronic inflammation of the cornea caused by an infection by herpes simplex type 1 virus.
lacrimal glands tear glands; they keep the eyes constantly moist.
lazy eye a loss or lack of vision in one eye due to misalignment of the eyes.
lens behind the iris, the transparent body that changes shape to focus on objects at various distances.
muscae volitantes the condition of seeing floating specks before the eyes.
myopia nearsightedness; the ability to see close up but not far away.
nystagmus jerking, involuntary movements of the eyes due to brain lesions or inflammation, alcohol or drug toxicity, or a congenital disorder.
ocular involving the eyes or vision.
oculomotor pertaining to movements of the eyes.
optic nerve the main nerve leading from the retina that transmits images in the form of electrical impulses to the brain.
orbit an eye socket.
photophobia extreme sensitivity to light, a symptom of an eye disease.
photopsia the condition of seeing flashes of light before the eyes, a symptom of an eye disease. Also known as scintillation.
pinkeye inflammation of the conjunctiva marked by redness of the eyeball.
pupil the dark spot surrounded by the iris; the iris makes it enlarge or shrink in response to light or strong emotion.
