Other Terms of the Eyes and Ears Lesson 9

Accommodation

Ability of the eye to change focus from distant to near

Cerumen

Earwax

Depth perception

The ability to see objects in three dimensions

Dilate

Make the opening of the pupil larger

Equilibrium

The state of balance

Lacrimation

Secretion of tears

Prosthesis

Artificial substitute for a diseased or missing body part

Ptosis (the "P" is silent)

Drooping of the upper eyelid

Snellen chart

Eye-test chart

Tinnitus

Ringing or buzzing sound in the ears

Visual acuity

The ability to identify letters and numbers at a distance

Sclera

the tough outer tissue that protects the entire eyeball. It is also known as the white of the eye.

Choroid

the middle layer of the eye that contains the blood vessels that nourish the eye.

Retina

the innermost layer of light-sensitive tissue that lines the back interior of the eye. Converts light into electrical impulses that travel through the optic nerve to the brain, which interprets them as images.

Astigmatism

A condition in which the eye does not focus properly because of uneven curvatures of the cornea.

Audiometry

The use of an audiometer to measure hearing acuity.

Barotrauma

Pressure-related ear discomfort that is often caused by changes in air pressure.

Cataract

The loss of transparency of the lens that causes a progressive loss of visual clarity.

Cochlear implant

An electronic device implanted behind the ear to restore certain hearing losses.

Diplopia

The perception of two images of a single object.

Glaucoma

A group of diseases characterized by increased intraocular pressure that causes damage to the retinal nerve fibers and to the optic nerve.

Hemianopia

Blindness in one half of the visual field.

Hyperopia

A defect in which light rays focus beyond the retina (also known as farsightedness).

Myopia

A defect in which light rays focus in front of the retina (also known as nearsightedness).

Nystagmus

Involuntary, constant, rhythmic movement of the eyeball.

Ophthalmoscopy

The visual examination of the fundus of the eye with an ophthalmoscope.

Optometrist

Specializes in measuring the accuracy of vision to determine whether corrective lenses are needed.

Otitis media

An inflammation of the middle ear.

Otomycosis

Fungal infection of the external auditory canal.

Otopyorrhea

Flow of pus from the ear.

Otorrhea

Any discharge from the ear.

Periorbital edema

Swelling surrounding the eye or eyes.

Photophobia

Excessive sensitivity to light that can be the result of migraines, excessive wearing of contact lenses, drug use, or inflammation.

Presbycusis

Gradual loss of sensorineural hearing that occurs as the body ages.

Presbyopia

The common changes in the eye that occur with aging.

Radial keratotomy

The surgical procedure to correct myopia by making incisions partially through the cornea, causing it to flatten.

Strabismus

Disorder in which the eyes point in different directions or are not aligned correctly.

Tonometry

The measurement of intraocular pressure.

Vertigo

Sense of whirling, dizziness, and the loss of balance, that often is combined with nausea and vomiting.

anterior chamber

the front part of the eye between the cornea and the iris.

posterior chamber

between the iris and the lens.

Conjunctiva

a clear, thin mucous membrane that covers the inner surface of the eyelids and the back and sides of the eye's outer surface.

Cornea

a transparent, dome-shaped membrane at the center of the front of the eye.

Auricle/Pinna

The medical term for the fleshy outer ear is the auricle or pinna. It is made up of cartilage and skin. The auricle or pinna captures sound waves and transmits them into the external auditory canal, or ear canal.

Ear canal

transmits sound waves to the tympanic membrane, located between the outer and middle ear.

Tympanic membrane

located between the outer and middle ear. When sound waves strike the tympanic membrane, the membrane vibrates and transmits the vibrations further, to the bones of the middle ear.

Malleus

Also known as the hammer.

Incus

Also known as the anvil.

Stapes

Also known as the stirrup.

Eustachian tube

the canal that connects the middle ear to the nasopharynx (the upper throat and the back of the nasal cavity). It controls the air pressure within the middle ear, making it equal to the air pressure outside the body.

Oval window

the membrane that separates the middle ear from the inner ear. Vibrations enter the inner ear through this structure.

Cochlea

shaped like a snail and contains the spiral organ of Corti, which is the receptor organ for hearing. It consists of tiny hair cells that translate the fluid vibration of sounds from its surrounding ducts into electrical impulses carried to the brain by sensory nerves.

Semicircular canals

canals that are lined with hair cells and filled with a liquid substance called endolymph. Every time the head moves, the endolymph moves the hair cells. The movements of the hair cells provide information about the body's orientation to the brain to help maintain balance.

Acoustic nerve

Coming from the inner ear and running to the brain is the eighth cranial nerve, this nerve carries both balance and hearing information to the brain.

Hair Cells

These are sensory receptors for both hearing and balance.

Sensorineural hearing loss

Caused by damage to the auditory nerve or hair cells in the inner ear

Conductive hearing loss

Sound waves not passing from the air to the fluid-filled inner ear; may be caused by a buildup of earwax, punctured eardrum, fluid in the middle ear, or scarring

Acoustic Reflectometry

Measures how much sound is reflected back from the eardrum, which can assess how much fluid is in the middle ear

Tympanometry

The use of air pressure to test for disorders of the middle ear

Otoplasty

Surgical repair of the pinna(outer ear)

Myringotomy

Incision into the eardrum to relieve pressure

Stapedectomy

Surgical removal of the stapes

Cochlear implant

Electronic device that directly stimulates the auditory nerve