Eyes Flashcards
name the 6 sets of extraocular muscles and the cranial nerve (CN) that innervates them
- superior oblique (CN IV - trochlear)
- medial rectus (CN III - oculomotor)
- inferior rectus (CN VI - abducens)
- inferior oblique (CN III - oculomotor)
- lateral rectus (CN III - oculomotor)
- superior rectus (CN III - oculomotor)
name and describe the 3 coats of the eye
- sclera = outer, fibrous
- chorioid = middle, vascular
- retina = inner, nervous
name the functions of the ciliary body, pupil + iris
- ciliary body = muscle for accommodation, release aqueous humour, controls thickness or iris, bulge to focus on near + flattens for far
- pupil = hole that light passes through, constricts / dilates
- iris = biconcave disc located anterior to pupil, refractory, helps focus
describe how an image formed on the retina compares with an objects actual appearance in the outside word
image formed is upside down + reversed from its actual appearance in the outside world
describe the lacrimal system
provides constant irrigation to keep the conjunctiva + cornea moist + lubricated
define the papillary light reflex, fixation + accommodation
- papillary light reflex = normal constriction of pupils when bright light shines on retina (no conscious control)
- fixation = reflex direction of eye towards an object, attracting our attention
- accommodation = adaption of eye near vision
concerning the pupillary light reflex, describe and contrast a direct light reflex, with consensual light reflex
optic nerve (CN II) carries sensory afferent message + then synapses with both sides of the brain
identify common age-related changes in the eye
- lacrimal gland involute (decrease tear production)
- infiltration of degenerative lipid material shows around limbus
- decrease pupil size
- lens loses elasticity, becomes hard + glass like
discuss the most common of decreased visual function in older adults
cataract formation, glaucoma, age-related macular degeneration, diabetic retinopathy
explain the statement of normal visual acuity (20/20)
numerator = distance at which patient can read the letters
denominator = distance at which a normal person can read the letters
describe the method of testing for presbyopia
hand help vision screening
to test for accommodation, the person focuses on a distant object, then shifts the gaze to a near object about 15cm away. At a near distance, you would expect the pupils to ____ and the axes of the eyes to ____
constrict
converge
concerning malalignment of the eye axes, contrast phobia with tropia
phoria = mild weakness when fusion is blocked
tropia = more severe constant malalignment
describe abnormal findings of tissue color that are possible on the conjunctiva and sclera and their significance
general reddening, cyanosis of lower lids, yellowing of sclera
describe pingueculae VS pterygium
pingueculae = yellowish patch / bump on conjunctiva that results in deposit of protein, fat and/or can often lead to a pterygium
pterygium = triangular growth on sclera
describe conjunctivitis
infection of conjunctivitis
aka pink eye
describe subconjunctival hemorrhage
small blood vessel in the white of the eye breaks
describe iritis
inflammation of iris + anterior chamber
describe acute glaucoma
iris blocks drainage angle of eye causing increase in pressure
define accommodation
adaptation of eye for near vision by increasing the curvature of the lens
define anisocoria
unequal pupil size
define arcus senilis
grey-white arc or circle around the limbus of the iris that is common with aging
define argyll Robertson pupil
no reaction of pupil to light but does constrict with accommodation
define arteriovenous crossing
crossing paths of an artery + vein in the ocular fundus
define bitemporal hemianopsia
loss of both temporal visual fields
define blepharitis
inflammation of the glands + eyelash follicles along the margin of eyelids
define cataract
opacity of the lens of the eye that develops slowly with aging + gradually obstructs vision
define chalazion
an infection or retention cyst of a meibomian gland, showing as a beady nodule on the eyelid
define conjunctivitis
infection of the conjunctiva “pinkeye”
define cotton wool spots
abnormal soft exudates visible as grey-white areas on the ocular fundus
define cup-disc ratio
ratio of width of the physiological cup to the width of optic disc, normally half or less
define dioptre
unit of strength of the lens settings on the ophthalmoscope that changes focus on the eye structure
define diplopia
double vision
define drusen
benign deposits on the ocular fundus that show as round yellow dots + occur commonly with aging
define ectropion
lower eyelid loose + rolling outward
define entropion
lower eyelid rolling inward
define exophthalmos
protruding eyeballs
define fovea centralis
area of sharpest + keenest vision; it is at the centre of the macula on the ocular fundus
define glaucoma
group of eye diseases characterized by increase intraocular pressure
define hordeolum
a stye; red, painful pustule that is a localized infection of the hair follicle at the eyelid margin
define lid lag
abnormal white rim of sclera visible between the upper eyelid + the iris when a person moves the eyes downward
define macula
a round, darker area of the ocular fundus that mediates vision only from the central visual field
define microaneurysm
abnormal finding of round punctuate red dots on the ocular fundus that are localized dilations of small vessels
define miosis
constricted pupils
define mydriasis
dilated pupils
define myopia
“nearsightedness”; refractive error in which near vision is better than far vision
define nystagmus
involuntary, rapid, rhythmic movement of eyeball
define O.D.
oculus dexter, or right eye
define optic atrophy
pallor of the optic disc due to partial or complete depth of optic nerve
define optic disc
area of the ocular fundus in which blood vessels exit + enter
define O.S.
oculus sinister, or left eye
define papilledema
stasis of blood flow out of the ocular fundus; sing of increased intracranial pressure
define pingueculae
yellowish elevated nodules caused by a thickening of the bulbar conjunctiva as a result of prolonged expsure to sun, wind, dust
define presbyopia
decrease in power of accommodation that occurs with aging
define pterygium
triangular opaque tissue on the nasal side of the conjunctiva that grows toward the centre of cornea
define ptosis
drooping of upper eyelid over the iris and possible covering the pupil
define red reflex
red glow that appears to fill the person pupil when the visualized through the ophthalmoscope
define strabismus
squint, crossed eye, disparity of the eye axes
define xanthelasma
soft, raised yellow plaques on the eyelids at the inner corners of the eyes
