ch 12 eye

eye

organ of vision

sclera

outer protective layer of the eye; the portion seen on the anterior portion of the eyeball is referred to as the white of the eye

cornea

transparent anterior part of the sclera, which is anterior to the aqueous humor and lies over the iris

choroid

middle layer of the eye, which is interlaced with many blood vessels that supply nutrients to the eye

iris

pigmented muscular structure that regulates the amount of light entering the eye by controlling the size of the pupil

pupil

opening in the center of the iris

lens

lies directly behind the pupil; focuses and bends light

retina

innermost layer of the eye, which contains the vision receptors

aqueous humor

watery liquid found in the anterior cavity of the eye. It provides nourishment to nearby structures and maintains shape in the anterior part of the eye

vitreous humor

jellylike substance found behind the lens in the posterior cavity of the eye that maintains its shape

meibomian glands

oil glands found in the upper and lower edges of the eyelids that help lubricate the eye

lacrimal apparatus

network of glands, ducts, canals, and sacs that produce and drain tears; the lacrimal gland produces tears, which then flow through the lacrimal ducts to cover the surface of the eye. tears drain into lacrimal canals, flow into the lacrimal sac (tear sac) and then into the nasolacrimal duct, which opens into the nasal cavity

optic nerve

carries visual impulses from the retina to the brain

conjuctiva

mucous membrane lining the eyelids and covering the anterior portion of the sclera

blephar/o

eyelid

conjuctiv/o

conjuctiva

cor/o, core/o, pupill/o

pupil

corne/o, kerat/o

cornea

dacry/o, lacrim/o

tear(s)

ir/o, irid/o

iris

ocul/o, ophthalm/o

eye

opt/o

vision

phac/o, phak/o

lens

retin/o

retina

scler/o

sclera

cry/o

cold

cyst/o

bladder, sac

dipl/o

two, double

is/o

equal

phot/o

light

ton/o

tension, pressure

bi-, bin-

two

-opia

vision (condition)

-phobia

abnormal fear of or aversion to specific things

-plegia

paralysis

aphakia

condition of without a lens (may be congenital, though often is the result of extraction of a cataract without the placement of an intraocular lens)

blepharitis

inflammation of the eyelid

blepharoptosis

dropping of the eyelid

Conjunctivitis

inflammation of the conjunctiva (commonly called pink eye)

dacryocystitis

inflammation of the tear (lacrimal) sac

diplopia

double vision

endophthalmitis

inflammation within the eye

iridoplegia

paralysis of the iris

iritis

inflammation of the iris

keratitis

inflammation of the cornea

keratomalacia

softening of the cornea (usually a bilateral condition associated with vitamin A deficiency)

leukocoria

condition of white pupil

oculomycosis

abnormal condition of the eye caused by a fungus

ophthalmalgia

pain in the eye

opthalmoplegia

paralysis of the eye (muscle)

phacomalacia

softening of the lens

photophobia

abnormal fear of (sensitivity to) light

retinoblastoma

tumor arising from a developing retinal cell (malignant, may be congenital; occurs mainly in children)

retinopathy

(any noninflammatory) disease of the retina (such as diabetic retinopathy)

scleritis

inflammation of the sclera

scleromalacia

softening of the sclera

xerophthalmia

condition of dry eye (conjunctiva and cornea)

amblyopia

reduced vision in one eye caused by disuse or misuse associated with strabismus, unequal refractive errors, or otherwise impaired vision. the brain suppresses images from the impaired eye to avoid double vision (commonly called lazy eye)

anisometropia

significant unequal refractive error between two eyes

astigmatism (Ast)

blurred vision caused by irregular curvature of the cornea or lens. Light refracts improperly, resulting in diffused, rather than points of light focusing on the retina.

cataract

clouding of the lens of the eye

chalazion

non-infected obstruction of an oil gland of the eyelid (also called meibomian cyst)

drusen

yellowish deposits located under the retina; commonly associated with aging and macular degeneration

glaucoma

eye disorder characterized by increase of intraocular pressure (IOP). if left untreated may progress to optic nerve damage and visual impairment or loss

hyperopia

farsightedness

hyphema

hemorrhage within the anterior chamber of the eye; most often caused by blunt trauma (also called hyphemia)

macular degeneration

progressive deterioration of the portion of the retina called the macula, resulting in loss of central vision. age-related macular degeneration (ARMD) is the lading cause of legal blindness in persons older than 65 years; onset occurs between the ages of 50 and 60

myopia

nearsightedness

nyctalopia

poor vision at night or in faint light (also called night blindness)

nystagmus

involuntary, jerking movements of the eyes

Pinguecula

yellowish mass on the conjunctiva that may be related to exposure to ultraviolet light, dry climates, and dust

presbyopia

impaired vision as a result of aging

pteryglum

thin tissue growing onto the cornea from the conjuctiva , usually caused by sun exposure

retinal detachment

separation of the retina from the choroid in the back of the eye

retinitis pigmentosa

hereditary, progressive disease marked by night blindness with atrophy and retinal pigment changes

strabismus

condition in which the eyes look in different directions; caused by dysfunction of the external eye muscles or an uncorrected refractive error (called cross-eyed when one eye turns in)

sty

infection of an oil gland of the eyelid

blepharoplasty

surgical repair of the eyelid

cryoretinopexy

surgical fixation of the retina by using extreme cold (carbon dioxide)

dacryocystorhinostomy

creation of an artificial opening between the tear (lacrimal) sac and the nose (to restore drainage into the nose when the nasolacrimal duct is obstructed or obliterated)

dacryocystotomy

incision into the tear (lacrimal) sac

iridectomy

excision (of part) of the iris

iridotomy

incision into the iris

keratoplasty

surgical repair of the cornea (corneal transplant)

sclerotomy

incision into the sclera

enucleation

surgical removal of the eyeball (also, the removal of any organ that comes out clean and whole)

LASIK (laser-assisted in situ keratomileusis)

laser procedure that reshapes the corneal tissue beneath the surface of the cornea to correct astigmatism, hyperopia, and myopia. it is a combination of excimer laser and lamellar keratoplasty. it differes from photorefractive keratectomy (PRK) in that it reshapes corneal tissue beneath the surface rather than on the surface

phacoemulsification

method to remove cataracts in which an ultrasonic needle probe breaks up the lens, which is then aspirated

photorefractive keratectomy (PRK)

procedure for the treatment of astigmatism, hyperopia, and myopia in which an excimer laser is used to reshape (flatten) the corneal surface by removing a portion of the cornea

retinal photocoagulation

intense beam of light from a laser condenses retinal tissue to seal leaking blood vessels, to destroy abnormal tissue or lesions, or to bond the retina to the back of the eye. used to treat retinal tears, diabetic retinopathy, wet macular degeneration, glaucoma, and intraocular tumors

scleral buckling

procedure to repair retinal detachment. A strip of sclera is resected, or a fold is made in the sclera. An exoplant is used to hold and buckle the sclera

trabeculectomy

surgical creation of an opening that allows aqueous humor to drain out of the eye to underneath the conjunctiva where it is absorbed; used to treat glaucoma by reducing intraocular pressure (laser trabeculoplasty may also be used)

vitrectomy

surgical removal of all or part of the vitreous humor (used to treat diabetic retinopathy)

fluorescein angiography

radiographic imaging of blood vessels (of the eye with fluorescing dye)

keratometer

instrument used to measure (the curvature of) the cornea (used for fitting contact lenses)

ophthalmoscope

instrument used for visual examination (of the interior) of the eye

ophthalmoscopy

visual examination of the eye

optometry

measurement of vision (also measurement of the eye and visual processing system)

pupillometer

instrument used to measure (the diameter of) the pupil

pupilloscope

instrument used for visual examination of the pupil