NCMA 111 - EYES

Eyebrows

Protects the eyes from moisture and debris; shields from bright light and contributes to facial expression

Eyelids

Upper and lower movable folds that protect the eyes from debris

Palpebral Fissure

Opening between the upper and lower lids that allows eye opening and regulates light entry

Meibomian Gland

Produces an oily substance that lubricates the lids and prevents rapid evaporation of tears

Conjunctiva

Thin mucous membrane that lubricates the eye and protects against microorganisms

Palpebral Conjunctiva

Portion that lines the inner surface of the lids

Bulbar Conjunctiva

Portion that covers the anterior surface of the sclera

Forniceal Conjunctiva

Flexible fold that connects the inner lining of the lids to the surface covering the sclera

Lacrimal Gland

Produces tear fluid that keeps the eye moist and cleansed

Tear Film

Combination of tear fluid and oily secretions that lubricates

Sclera

Tough white outer layer that supports internal structures and maintains the shape of the eyeball

Cornea

Transparent and avascular structure that bends incoming light toward deeper structures of the eye

Uvea

Middle vascular layer that nourishes the eye and includes three main components

Iris

Pigmented circular structure that regulates the amount of light entering by adjusting the opening size

Ciliary Body

Structure that changes the curvature of the lens for focusing and produces intraocular fluid

Choroid

Highly vascular layer that supplies oxygen and nutrients and absorbs excess light

Retina

Inner light-sensitive layer that converts light into nerve impulses using specialized cells

Rods

Photoreceptors responsible for vision in dim light and peripheral awareness

Cones

Photoreceptors responsible for color perception and sharp central vision

Optic Disc

Region where nerve fibers exit the eye; lacks photoreceptors resulting in a blind spot

Lens

Flexible transparent structure that fine-tunes and focuses light onto the inner layer

Vision Light Pathway

Sequence where light passes through cornea aqueous humor pupil lens vitreous humor and reaches the retina

Vision Neural Pathway

Route where impulses travel from retina to optic nerve then optic chiasm optic tract and finally the visual cortex

Superior Rectus

Elevates the eye and is controlled by cranial nerve III

Superior Oblique

Depresses and rotates the eye and is controlled by cranial nerve IV

Lateral Rectus

Abducts the eye and is controlled by cranial nerve VI

Inferior Oblique

Elevates and rotates the eye and is controlled by cranial nerve III

Inferior Rectus

Depresses the eye and is controlled by cranial nerve III

Medial Rectus

Adducts the eye and is controlled by cranial nerve III

Exophthalmos

Protrusion of the eyeball where the white part is visible above the colored portion

Entropion

Condition where the lid turns inward causing lashes to rub against the eye

Ectropion

Condition where the lid turns outward exposing the inner surface

Ptosis

Drooping of the upper lid due to nerve damage muscle weakness or neurologic disorder

Xanthelasma

Yellowish lipid deposits commonly found on the eyelids

Chalazion

Localized painless swelling caused by blockage of an oil-secreting structure in the lid

Hordeolum

Acute painful infection of a gland in the eyelid commonly known as a stye

Legally Blind

Condition where best corrected vision is 20 over 200 or worse

Presbyopia

Age-related decrease in lens flexibility resulting in difficulty focusing on near objects

Myopia

Condition where light focuses in front of the retina causing difficulty seeing distant objects

Hyperopia

Condition where light focuses behind the retina causing difficulty seeing near objects

Ishihara Test

Assessment tool used to detect red green color vision deficiency

Allen Card Test

Picture-based vision test performed at a distance of about 3 meters for young children

Macular Degeneration

Degenerative condition affecting central vision and color perception

Conjunctivitis

Inflammation characterized by redness and discharge from the eye surface

Subconjunctival Hemorrhage

Bright red patch caused by bleeding underneath the surface membrane

Yellow Sclera

Discoloration associated with elevated bilirubin levels

Blue Sclera

Bluish discoloration linked to a connective tissue disorder affecting bone strength

Pterygium

Fleshy growth extending from the surface membrane toward the cornea

Corneal Arcus

Grayish or white ring around the corneal edge due to lipid deposition

PERRLA

Acronym describing pupils that are equal round and responsive to light and focusing

Mydriasis

Abnormally enlarged pupil size greater than 6 millimeters

Miosis

Abnormally constricted pupil size less than 2 millimeters

Anisocoria

Unequal size between the two pupils

Nystagmus

Involuntary rhythmic oscillation of the eyes

Strabismus

Failure of both eyes to align properly resulting in deviation

Cover Uncover Test

Procedure used to evaluate alignment by observing eye movement when one is covered

Confrontation Test

Screening method used to assess peripheral vision by comparing fields with the examiner