chap 16 Flashcards
functions of eyelids
- protect the eye from foreign body and limits light entering eye
- distribute tears
function of eyelashes
filters dust and dirt
functions of lacrimal apparatus
- produces tears
- provides lubrication
function of extraocular muscles
control directions of eye movement
external layer
sclera and cornea
middle layer
iris, ciliary body, lens
inner most layer
retina
vision
- vision field
- visual perception
- pupillary light reflex
- accomodation
vision field
what a person sees with one eye
visual perception
conducted to optic nerve & interpreted
accommodation
allows eye to focus on near objects
glaucoma test
“puff of air”
lifestyle and health practices (eyes)
- exposure to certain conditions/substances
- sunglasses
- vision loss?
- visual aids(contacts/glasses)
- diet/nutrition
- smoker
physical exam of eyes
- test visual acuity
- test visual fields
- perform corneal light reflex
- perform cardinal fields of gaze test
example of visual acuity test
snellen eye chart
PERRLA
pupils are equal, round, reactive to light, accommodation
nutrients good for eyes
- omega 3
- betacarotine
- fatty acids
dark skinned people consideration
- brown pigmented spot on sclera
- greater incidence of glaucoma in African decent
asian people consideration
epicanthal fold at medial canthus giving an almond shape appearance
warmer climate or snow fields consideration
greater incidence of cataracts
glaucoma
damage to the optic nerve
symptoms of glaucoma
- mostly asymptomatic
- loss of peripheral/side vision
- seeing halos around lights
- vision loss
- redness in eye
- eye looks hazy
risk factors for glaucoma
- age
- family history
- farsighted/nearsighted
- eye injury
- medications
- diabetes
- HTN
- poor circulation
macular degeneration
blurred or no vision in the center of visual field
symptoms of macular degeneration
- early stages symptomless
- wavy/blurred vision
- visual distortion
- loss of central vision
- change in perception of color
- need for brighter light to see
risk factors for macular degeneration
- age
- smoking
- family history
- gender
- obesity
- race
- light eye color
- prolonged sun exposure
- HTN
- CV disease
- inactivity
cataracts
- clouding of lens
- “looking out foggy window”
symptoms of cataracts
- clouded/blurred/dim vision
- increasing difficulty w/ night vision
- sensitivity to light
- need for brighter light for reading, etc
- halos around lights
- frequent changes in eye prescription
- fading or yellowing of colors
- double vision in single eye
risk factors for cataracts
- age
- diabetes
- excess exposure to sunlight
- smoking
- obesity
- HTN
- previous eye injury/trauma
- previous eye surgery
- medications
- alcohol
ptosis
drooping eye
ectropion
outward turned lower lid
CN II
responsible for vision
CN III, IV, VI
responsible for movement of eye
CN V
conveys sensory data from cornea
CN VII
closes eyelids
