PERLS207 Lecture : Visual Impairment

• School: University of Alberta
• Department: Physical Education, Recreation and Leisure Studies
• Course: PERLS207
• Professor: Joanna Clair

Document Summary

1. visual acuity: central vision or refractive vision (20/20 vs. 20/50) Problems with refractive vision: myopia (near-sighted, light focusses in front of retina, can see close, hyperopia (far-sighted, light focusses behind retina, can see far, astigmatism (light focusses on 2 points) 2. field of vision: peripheral vision (normally 180 , problems with peripheral vision (tunnel vision) Motion perception (3/200 to 5/200) (only see movement at 3 feet) Light perception ( <3/200) can see light @ 3 feet that normal vision can see @200. 80-90% have some residual vision, 10-20% are totally blind. Macular degeneration: breakdown of macula, thinning of retina, bleeding, affects central field of vision, risk factors: aging, smoking, heredity, leading cause of vision loss in ppl over 50. Glaucoma: fluid pressure on optic nerve, affects peripheral vision, risk factors: age, heredity. Cataracts: clouding of lens, blurriness, decreased colour, chemical change in lens due to: aging, medication, heredity, leading cause of blindness in developing worlds.