Chapter 31

Strabismus

failure of the eyes to track together, which means that both eyes do not look in the same direction at the same time.

Hyperopia

farsightedness

Cones

function in bright light and detect color

Rods

highly sensitive to light and can function in dim light

When light enters the eye and focuses behind the retina, a person has?

hyperopia. This disorder occurs when the eyeball is too short from the anterior to the posterior wall.

Glaucoma

increased intraocular pressure

nystagmus

involuntary movement of one or both eyes

Ménière disease

is a disorder of the inner ear. It is characterized by vertigo, tinnitus, progressive hearing loss, and sometimes a feeling of pressure or fullness in the ear.

Otitis media

is an inflammation of the normally air-filled middle ear that results in a collection of fluid behind the tympanic membrane.

Conductive hearing loss

is caused by a problem originating in the external or middle ear that prevents sound vibrations from passing through the external auditory canal, limits the vibration of the tympanic membrane, or interferes with the passage of bone-conducted sound in the middle ear.

Dry macular degeneration

is caused by the breakdown of light-sensitive cells in the region of the macula; the wet form is seen when new blood vessels behind the retina form and leak blood and fluid into the macula.

optometrist

is not a medical doctor, but he or she is licensed and has earned a degree as a doctor of optometry (OD).An optometrist can perform eye examinations, diagnose vision problems and eye diseases, prescribe ophthalmic medications, and treat visual defects through corrective lenses and eye exercises.

amblyopia

lazy eye/ dimness of vision

Audiometry

measures the lowest intensity of sound an individual can hear

Myopia

nearsightedness

Rods and cones convert light into?

nerve impulses

Cerumen

normally is a soft, yellowish, waxy substance that lubricates the external auditory canal.

Astigmatism?

occurs when light rays entering the eye are focused irregularly. This usually occurs because the cornea or the lens is not a smooth sphere, but rather has an irregular shape

Myopia?

occurs when light rays entering the eye focus in front of the retina, causing objects at a distance to appear blurry and dull.

Serous otitis media occurs because

of a buildup of clear fluid in the middle ear; patients complain of a full feeling and some hearing loss.

Symptoms of corneal abrasion include

pain, inflammation, tearing, and photophobia.

Signs and Symptoms of Refractive Errors Refractive errors in vision?

can lead to squinting, frequent rubbing of the eyes, and headaches. The individual notices blurred vision, fading of words at reading level, or both. Some refractive errors are familial in nature.

chronic open-angle glaucoma

the channels that drain the fluid malfunction, and over time aqueous humor builds up, resulting in increased pressure, which affects the blood supply to the retina and the optic nerve

Otorhinolaryngology

the medical specialty that deals with the ear, nose, and throat.

acute closed-angle glaucoma,

the opening of the drainage system narrows or closes completely, causing a sudden increase in IOP.

Ophthalmology

the science of the eye and its disorders and diseases

Opticians

trained to fill prescriptions written by ophthalmologists and optometrists for corrective lenses by grinding the lenses and dispensing eyewear

The Weber test

used if the patient reports that hearing is better in one ear than in the other.

ophthalmoscope is

used to examine the interior of the eye.

Hordeolum (sty)

A localized, purulent infection of a sebaceous gland of the eyelid. The area is inflamed, swollen, and painful. The infection usually is caused by staphylococci, and it is treated with warm compresses and topical or systemic antibiotics.

Chalazion

A small cyst that results from blockage of a meibomian gland (sebaceous gland) and lubricates the posterior margin of each eyelid. The cyst can become infected, inflamed, swollen, and painful. It may disappear spontaneously or may need to be removed surgically.

Ishihara Color Vision Test

Defects in color vision are classified as congenital or acquired.

Treatment of Refractive Errors

Eyeglasses and contact lenses are the traditional treatments for visual acuity problems caused by refractive errors.

The last line the patient can read without squinting or straining and with no more than two mistakes is the line recorded in the patient's record for that eye.

How to test eyes

Conjunctivitis

Inflammation of the conjunctiva caused by irritation, allergy, or bacterial infection. Bacterial conjunctivitis (pinkeye) is highly contagious and produces a purulent discharge. Symptoms include inflammation, swelling and itching of the sclera, photophobia, and tearing. Bacterial infections are treated with antibiotic ophthalmic preparations

Keratitis

Inflammation of the cornea that results in superficial ulcerations. It can be caused by the herpes simplex virus, bacteria, or fungi, or it may develop as a result of corneal trauma (e.g., intense light). Symptoms include inflammation, tearing, pain, and photophobia. The condition is treated with ophthalmic ointments, eyedrops, and use of an eye patch.

Blepharitis

Inflammation of the glands and lash follicles along the margins of the eyelids that may be caused by staphylococcal infection, allergies, or irritation. Symptoms include itching and inflammation along the eyelash margins; the condition is treated with antibiotic ophthalmic ointment.

Ear Irrigation

Irrigation of the ear is done to remove excessive or impacted cerumen, to remove a foreign body, or to treat the inflamed ear with an antiseptic solution

Instillation of Eye Medication

Liquid drops usually are supplied in small squeeze bottles with tips that allow one drop at a time to be dispensed, or the bottle may contain a dropper with a small rubber attachment used to dispense the medication by drops.

PERRLA

P Pupils E Equal R Round R Reactive to L Light (and) A Accommodation

How to test color blindness

The test should be administered in a quiet room that is well illuminated by sunlight, not by artificial lighting. If this cannot be done, the best situation possible is created by adjusting lights to resemble the effect of natural daylight. The test uses 14 color plates.

cataract

a cloudy or opaque area in the normally clear lens of the eye that blocks the passage of light into the retina, causing impaired vision.

Corneal abrasion usually is caused by

a foreign body in the eye or by direct trauma, such as from poorly fitting or dirty contact lenses.

ophthalmologist

a physician who specializes in the diagnosis and treatment of disorders and diseases of the eye

The Rinne test is designed to

compare air conduction sound with bone conduction sound.

Macular

degeneration is progressive deterioration of the macula lutea, which causes loss of central vision; the patient can see only the edges of the visual field

otitis externa, or swimmer's ear. Otitis externa may be caused by

dermatologic conditions, such as seborrhea or psoriasis, trauma to the canal, or continuous use of earplugs or earphones.

diplopia

double vision

As people age, the lens of the eye becomes less flexible, and the ciliary muscles weaken; consequently, changing the point of focus from distance to near becomes difficult. This is called?

presbyopia. The condition results in difficulty seeing at reading level.

The eye is irrigated to

relieve inflammation, remove drainage, dilute chemicals, or wash away foreign bodies.

The outermost layer is made up of the white, opaque...

sclera (SKLAYR a) and the transparent cornea.