Assisting in Ophthalmology

strabismus

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

eyebrows

help keep irritants out of the eyes

vitreous humor

helps maintain normal pressure within the eye and provides nutrients to the lens and the cornea

eyelid

helps protect the eye from trauma

conjunctivitis

inflammation of the conjunctiva caused by irritation, allergy, or bacterial infection

keratitis

inflammation of the cornea that results in superficial ulcerations

blepharitis

inflammation of the glands and lash follicles along the margins of the eyelids that may be caused by staphylococcal infection, allergies, or irritation

lens

is a transparent, biconvex body that helps focus light after is passes through the cornea

eyelashes

line the margins of the eyelids and help trap foreign particles

hordeolum (stye)

localized purulent infection of a sebaceous gland of the eyelid.

diplopia

means double vision

optometrist

not a medical doctor but is licensed and has earned a degree as a Doctor of Optometry (OD)

astigmatism

occurs when light rays entering the eye are focused irregularly, occurs because the cornea or lens is not a smooth sphere.

myopia (nearsightedness)

occurs when light rays entering the eye focus in front of the retina, causing objects at a distance to appear blurry and dull; eyeball is elongated from the anterior to the posterior wall

glaucoma

one of the most common and serious ocular disorders is a group of diseases known as _____. Characterized by increased intraocular pressure, which damages the optic nerve and causes blindness if left untreated

sclera

outtermost layer is made up of the white, opaque ______ and the transparent cornea. tough fibrous lining that protects the entire eyeball lying with the orbit

corneal abrasion

pain, inflammation, tearing, photophobia, usually is caused by a foreign body in the eye or by direct trauma such as from poorly fitting or dirty contact lenses

ophthamologist

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

choroid posterior

posterior portion of the middle layer of the eye. It's the eye's vascular layer and it contains many blood vessels that supply nutrients to the outer layers of the retina.

tonometer

an instrument used to measure intraocular pressure

choroid anterior

anterior part of this layer, creates the iris and the ciliary body.

eyes

are the smallest, yet most detailed and complex, organs of the body

presbyopia

as people age, lens of the eye becomes less flexible, and the ciliary muscles weaken; consequently changing the point of focus from distance to near becomes difficult

visual impulse

begins with the passage of light through the cornea, where the light is refracted; then passes through the aqueous humor and the pupil into the lens

fovea centralis

small pit in the center of the retina that is considered the center of clearest vision

rods

structures in the retina of the eye that form the light-sensitive elements

cones

structures in the retina that make the perception of color possible

error of refraction

that the light rays are not refracted or bend properly and consequently do not focus correctly on the retina

optic nerve

the second cranial nerve which carries impulses for the sense of sight

conjunctiva

thin mucous membrane that lines the eyelid and covers the outside of the eyeball except for the most central portion, which is covered by the cornea

eye irrigation

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

opticians

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

hyperopia (farsightedness)

when light enters the eye and focuses behind the retina; eyeball is too short from the anterior to the posterior wall

cornea

acts as a clear window that allows light to enter the eye. Also refracts or changes, the direction of light rays after they enter the eye

eyes blink every

2 to 3 seconds, causing lacrimal gland to secrete tears

nystagmus

a constant, involuntary movement of one or both eyes is called

refraction

ability of the lens of the eye to blend parallel light rays coming into the eye so that the rays are focused simultaneously on the retina

cataract

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

iris

colored portion of the eye, contains muscles that regulate the size of the pupil according to the intensity of the light

ciliary body

contains both the muscle, which regulates the shape of the lens and the processes which secrete aqueous humor

retina

delicate tissue, composed of light-sensitive neurons that convert light into neurological impulses

distance visual acuity (Snellen chart)

displays various letters of the alphabet, which the patient must identify in ever smaller font sizes

blepharoptosis

drooping of the upper eyelid that can be caused by a disorder of the third cranial nerve, muscular weakness as seen in muscular dystrophy, or myasthenia gravis

chalazion

small cyst that results from blockage of a sebaceous gland that lubricates the posterior margin of each eyelid

gonioscopy

procedure in which a mirrored optical instrument is used to visualized the filtration angle of the anterior chamber of the eye; the procedure is used to diagnose glaucoma

macular degeneration

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

bony orbit

protects and supports the eye

PERRLA

pupils equal around reactive to light and accommodation

amblyopia

reduction or dimness of vision with no apparent organic cause; often referred to as a lazy eye syndrome

optic disk

region at back of the eye where the optic nerve meets the retina' it is considered the blind spot of the eye, because it contains only nerve fibers and no rods or cones and thus is insensitive to light

vision

requires light and depends on the proper functions of all parts of the eye

ophthamology

science of the eye and its disorders and diseases

Ishihara Color Vision Test

simple, convenient and accurate procedure that detects total color-blindness as well as red-green blindness that is prevalent in congenital blindness