EYES I Flashcards
LIGHT REACTION
A light beam shining onto one retina causes _______ in that eye, termed the direct
reaction to light, and in the contralateral eye, the
consensual reaction to light.
pupillary constriction
Near reaction
When a person shifts gaze from a far object to a near object, the pupils constrict This
response, like the light reaction, is mediated by the
___________ nerve. Coincident with this pupillary
constriction, but not part of it, are (1) ________ of the
eyes, a bilateral medial rectus movement; and (2) _____, an increased convexity of the lenses
caused by contraction of the ciliary muscles.
occulomotor nerve
convergence
accomodation
EXTRAOCULAR MOVEMENTS
Nerve damage or injury to the muscle, due to head
trauma, congenital causes, or central lesions, can cause
aberrations in this yoked system and lead to ___________.
diplopia (double vision)
vision changes
Difficulty with close work suggests _________
(farsightedness) or _______(aging vision), and,
difficulty with distance vision, suggest ________
(nearsightedness).
hyperopia
presbyopia
myopia
vision changes
If painful, causes are usually in the cornea and anterior
chamber such as corneal ulcer, uveitis, traumatic
__________, and acute angle closure glaucoma.
hyphema
double vision
__________is seen in lesions in the brainstem or
cerebellum and with weakness or paralysis of one or
more extraocular muscles,
as in _________ diplopia from
palsy of CN III or VI
______diplopia from palsy of CN
III or IV.
Diplopia in one eye, with the other closed,
suggests a problem in the ocular surface, cornea, lens,
or macula.
diplopia
horizontal
vertical
VISUAL DEFECTS
Occlusion of a branch of the central retinal artery may cause a horizontal altitudinal) defect. Ischemia of the optic nerve can produce a similar defect.
horizontal defects
VISUAL DEFECTS
A lesion of the optic nerve and, of
course, of the eye itself, produces unilateral monocular blindness.
blind right eye (right optic nerve)
VISUAL DEFECTS
A lesion at the optic chiasm (such as a pituitary tumor), may involve only fibers crossing over to the opposite side.
Since these fibers originate in the nasal half of each retina, visual loss involves the temporal half of each field.
bilateral hemianopsia
VISUAL FIELD DEFECTS
A lesion of the optic tract, interrupts fibers originating on the same side of both eyes.
Visual loss in the eyes is, therefore, similar (homonymous) and involves half of each field (hemianopsia).
left homonymous hemianopsia
VISUAL FIELD DEFECTS
A partial lesion of the optic radiation in the temporal
lobe, may involve only a portion of the nerve fibers, producing, for
example, a homonymous quadrantic (“pie in the sky”) defect.
homonymous left superior quadratic defect
VISUAL FIELD DEFECT
A complete interruption of fibers in the optic radiation, produces a visual defect similar to that produced by a lesion of the optic tract.
left homonymous hemianopsia
Variations and Abnormalities of
the Eyelids
________ is a drooping of the upper lid. Causes include senescence, myasthenia gravis, damage to the oculomotor nerve (CN III), and damage to the sympathetic nerve supply (Horner syndrome).
A weakened muscle, relaxed
tissues, and the weight of herniated fat may cause senile _________.
________ may also be congenital
ptosis
VARIATIONS AND ABNORMALITIES OF THE EYELIDS
______ more common in the elderly, is an inward turning of the lid margin.
The lower lashes, which are often invisible when turned inward, irritate the conjunctiva and lower cornea
This is different from _______where there is aberrant inward growth of the eyelashes, but the eyelid position remains normal.
entropion
trichiasis
EYELID VARIATIONS AND ABNORMALITIES
In __________, the lower lid margin turns outward, exposing the palpebral
conjunctiva. When the punctum of the lower lid turns outward, the eye no longer drains well, and tearing occurs.
_______ is also more common in
older adults.
entropion
trichiasis
EYELID VARIATIONS AND ABNORMALITIES
In ______, the lower lid margin turns outward, exposing the palpebral
conjunctiva. When the punctum of the lower lid turns outward, the eye no longer drains well, and tearing occurs.
___________ is also more common in
older adults.
ectropion
EYELID VARIATIONS AND ABNORMALITIES
A wide-eyed stare suggests retracted eyelids.
Note the rim of sclera between he upper lid and the iris.
Retracted lids and “lid lag” when eyes move from up to down markedly increase the likelihood of hyperthyroidism, especially when accompanied by a fine tremor, moist skin, and heart rate >90 beats/min
lid retraction
exopthalmos
_________ describes protrusion of the eyeball, a common feature of
thyroid eye disease, triggered by autoreactive T lymphocytes.
exophthalmos
LUMPS AND SWELLINGS IN AND AROUND EYES
harmless yellowish triangular nodule in the bulbar conjunctiva on either side of the iris
Appears frequently with aging, first on the nasal and then on
the temporal side.
pinguela
LUMPS AND SWELLINGS IN AND AROUND EYES
A benign, usually painless localized ocular inflammation of the episcleral
vessels.
Vessels appear movable over the scleral surface.
May be nodular or show only redness and dilated vessels.
episcleritis
LUMPS AND SWELLINGS IN AND AROUND EYES
A painful, tender, red infection at the inner or outer margin of the eyelid, usually from
_____________(at the inner margin—from an obstructed
meibomian gland; at the outer margin—from an obstructed eyelash follicle or
tear gland).
stye
stahphylococcus aureus
LUMPS AND SWELLINS IN THE EYE S
A subacute nontender, usually painless nodule caused by a blocked meibomian gland.
May become acutely inflamed but, unlike a stye, usually points inside the lid rather than on the lid margin.
chalazion
LUMPS AND SWELLING AROUND THE EYE
Slightly raised, yellowish, well-circumscribed cholesterol-filled plaques that
appear along the nasal portions of one or both eyelids. Half of affected
patients have hyperlipidemia; it is also common in primary biliary cirrhosis
xanthelasma
LUMPS AND SWELLING AROUND THE EYE
A chronic inflammation of the eyelids at the base of the hair follicles, often
from S. aureus. There is also a scaling seborrheic variant.
blepharitis
