Chapter 16 – Eyes (Lecture Review)

Vocabulary flashcards summarizing anatomical structures, physiological functions, assessment techniques, common disorders, and abnormal findings of the eye as presented in the Chapter 16 lecture.

Eyelids

Movable skin folds that protect the eye, distribute tears, and limit the amount of light entering.

Canthus (inner / outer)

The medial and lateral angles where the upper and lower eyelids meet.

Palpebral fissure

The elliptical open space between the eyelids.

Conjunctiva

Transparent mucous membrane lining eyelids and covering sclera; keeps eye moist and protected.

Lacrimal apparatus

Gland and ducts that produce and drain tears through the puncta into the nasolacrimal duct.

Extra-ocular muscles

Six muscles that control eye movement and maintain parallel alignment.

Sclera

Tough, white outer layer of the eye providing structure and protection.

Cornea

Transparent anterior part of sclera; refracts light and is avascular.

Iris

Colored muscular ring controlling pupil size and light entry.

Pupil

Central opening in the iris that regulates the amount of light entering the eye.

Lens

Biconvex structure behind iris that changes shape to focus light on the retina.

Retina

Inner layer containing photoreceptors that convert light into nerve impulses.

Optic disc

Yellow-orange area where optic nerve exits; lacks photoreceptors (blind spot).

Macula

Small, highly sensitive area of central vision on the retina.

Anterior chamber

Space between cornea and iris filled with aqueous humor.

Humors (aqueous & vitreous)

Fluids that maintain intra-ocular pressure and eye shape.

Arcus senilis

Gray-white ring at corneal edge in older adults; benign lipid deposit.

Presbyopia

Age-related loss of near focusing ability due to decreased lens accommodation.

Pseudoptosis

Apparent lid drooping from loss of skin elasticity in aging adults.

Floaters

Small moving spots due to vitreous debris; common with age or myopia.

Pupillary light reflex

Constriction of pupils when light shines; requires CN II (sensory) & CN III (motor).

Accommodation

Adjusting lens shape and ocular convergence for near vision.

Direct light reflex

Pupil constriction in the eye receiving light.

Consensual light reflex

Simultaneous constriction of the opposite pupil when light is shone in the other eye.

PERRLA

Acronym for Pupils Equal, Round, Reactive to Light and Accommodation – normal documentation.

Anisocoria

Unequal pupil sizes; normal if <0.5 mm, otherwise may indicate neurologic or ocular disease.

Miosis

Constricted, fixed pupils; may result from narcotics, drops, or brain damage.

Mydriasis

Dilated, fixed pupils; can signify CNS injury, deep anesthesia, or circulatory collapse.

Horner’s syndrome

Triad of miosis, ptosis, and anhidrosis from sympathetic nerve interruption.

Snellen chart

Wall chart used at 20 ft to measure distant visual acuity (CN II).

E-chart

Snellen variation using letter ‘E’ for non-literate or language-barrier clients.

Jaeger card

Hand-held card at 14 in to test near vision; detects presbyopia.

Confrontation test

Screens peripheral vision by comparing examiner and patient visual fields.

Corneal light reflex (Hirschberg)

Assesses parallel alignment by observing symmetrical light reflection on corneas.

Cover test

Detects ocular misalignment (phoria or tropia) by alternately covering eyes.

Cardinal fields of gaze

Six positions testing extra-ocular muscles and CN III, IV, VI; observes for nystagmus or lid lag.

Phoria

Latent ocular misalignment appearing only during cover test.

Strabismus (tropia)

Constant ocular misalignment (e.g., esotropia, exotropia).

Nystagmus

Involuntary oscillating eye movements, may indicate vestibular or cerebellar dysfunction.

Ptosis

Drooping upper eyelid from CN III palsy or muscular weakness (myasthenia gravis).

Exophthalmos

Protruding eyes with lid retraction, commonly from Graves disease (hyperthyroidism).

Enophthalmos

Sunken eyeballs due to fat loss, dehydration, or trauma.

Entropion

Inward turning lower lid; lashes irritate cornea and conjunctiva.

Ectropion

Outward turning lower lid causing dryness and exposure keratitis.

Xanthelasma

Yellowish cholesterol-rich plaques on eyelids near canthus; often benign.

Periorbital edema

Swollen lids from local infection, crying, CHF, renal failure, or myxedema.

Blepharitis

Inflammation of eyelid margins with redness and crusting, often staphylococcal.

Conjunctivitis

Inflamed conjunctiva causing generalized redness (‘pink eye’); viral, bacterial, or allergic.

Episcleritis

Localized, noninfectious inflammation of the superficial scleral tissue.

Subconjunctival hemorrhage

Bright-red scleral patch from ruptured vessel; benign, resolves in 1–2 weeks.

Corneal abrasion

Superficial corneal injury producing a ‘shattered’ appearance and pain.

Cataract

Lens opacity causing blurred, foggy vision; risk increases with age, diabetes, alcohol, injury.

Glaucoma

Optic-nerve damage from increased intraocular pressure; includes primary open-angle and acute narrow-angle types.

Primary open-angle glaucoma

Chronic, painless clogging of drainage canal causing gradual peripheral vision loss.

Acute narrow-angle glaucoma

Sudden blockage of drainage by iris; severe eye pain, halos, headache, nausea – medical emergency.

Macular degeneration

Degenerative changes in macula leading to central vision loss; risks: age, smoking, light iris, hypertension.

Myopia

Nearsightedness; impaired distant vision where Snellen denominator exceeds numerator.

Hyperopia

Farsightedness; can read better at distance than near.

Scotoma

Isolated blind spot within an otherwise normal visual field; may herald retinal disease.

Halos

Rainbow rings around lights, often indicating narrow-angle glaucoma.

Night blindness

Poor vision in low light due to optic atrophy, glaucoma, or vitamin A deficiency.

Diplopia

Double vision frequently associated with increased intracranial pressure or ocular muscle imbalance.

Epiphora

Excessive tearing from irritants or lacrimal obstruction.

Retinal detachment

Separation of retina causing sudden floaters, flashes, or shadow curtain; requires urgent laser repair.

Puncta

Tiny openings at medial lids through which tears drain into nasolacrimal duct.

Hordeolum (stye)

Acute staphylococcal infection of eyelid gland producing painful pustule.

Chalazion

Firm, painless nodule from blocked meibomian gland on eyelid.