week 10 Flashcards
eye conditions in canada
5.6mil ppl have eye disease that can cause vision loss
most common = cataracts
10-15% only see dark
- rest see shapes, shadows, etc.
visual acuity and field of vision
visual acuity: sharpness/clarity of image
- measured via shellen test
field of vision: angle of vision/area person can see w/o moving eyes
colour blindness measured w ishiara plate test
types of blindness
legal blindness: visual acuity 20/200 or less in BOTH eyes, best corrected (w glasses)
- or visual field of 20deg or narrower, like roll over eye
low vision: visual acuity 20/60, best corrected
deaf blindness: both hearing and vision loss
canadian stats blindness
1/4 will be legally blind by 75
68% unemployed, most don’t get aids
vision rehab not funded by gov
25% kids vision loss…lazy eye, cross eye can cause blindness
75% preventable i.e. check ups, not smoking, drink moderately
hyperopia vs myopia
myopia: nearsighted, elongated eyeball
hyperopia: farsighted, eyeball shorter and light rays focus past retina
astigmatism
irregular cornea shape distorts lens
presbyopia
loss of elasticity of lens and weak ciliary muscle
gradual loss
nystagmus
lazy eye, invol mvmnt
stabismus
cross eye, misalignment
glaucoma
group of conditions w many causes
diabetic retinopathy
damage to retina bcs of diabetes
retinal detachment
sensory layer detached from pigmented layer, lose blood supply
retinitis pigmentosa
progressive loss of peripheral vision
blindness may occur
macular degeneration
part of eye for fine detail and central vision degenerates
major concerns for blind ppl
attitudes of others
travel skills: maintain independence
- white cane is to check for objects, but also lets others know to move
literacy and access to info: 10% blind can read braille