Blindness Flashcards
(30 cards)
Acuity
How far you can see
Visual field
Peripheral vision (normal = 180 degree)
Legal blindness (2 options)
- 20/200 or lower with best correction (acuity = 10%)
- Visual field < 10 degree (tunnel vision)
Total blindness
- Inability to recognize a strong light shown directly into the eye
- > 80% have residual vision (<20% are totally blind)
Sports Classification (3)
- B1: total blindness to very low residual vision
- B2: low residual vision
- B3: better residual vision
Sports Classification - B1
- No light perception in either eye up to light perception and inability to recognize the shape of a hand in any direction and at any distance
- Sports:
- Swimming, Judo, Wrestling (independently)
- Track even with guide
Sports Classification - B2
- Ability to recognize the shape of a hand up to a visual acuity of 2/60 and/or limitation of field of vision of 5 degree
- Can do many activities independently with sunlight/bright indoor light
Sports Classification - B3
- 2/60 to 6/60 (20/200) vision and/or field of vision between 5 and 20 degrees
- Don’t use guides for most activities (except high risk ex rock climbing)
Blind Alpine Skier - Recreational Skiing
99% of blind people are guided from behind by their sighted guide
Blind Alpine Skier - Ski Racing
Almost 100% skiers are guided from the front
Incidence in QC
- 8 000 people are legally blind
- 50% over 65 years old
- 10% under 20 years old
Reality of vision loss
- Only 1/3 of adults with vision loss are unemployed
- 3x more likely to experience depression
- Greater risk of social isolation
Eye Anatomy - Retina cells
Convert light into neutral impulses
Eye Anatomy - Blood vessels
Supply nutrients to eye structures including retina cells
Eye Anatomy - Macula
- Central vision
- Area use for focusing the vision
Eye Anatomy - Optic nerves
- Connects vision to the occipital lobe (AP)
- Deteriorates by glaucoma
Diabetic Retinopathy
- Leading cause of blindness
- Between 20 and 65 years old
- Complication of diabetes
- Damage to tiny blood vessel inside retina (stop receiving blood) = loss of retina cells = not reversible
Cataracts
- More common in seniors
- Lens become clouded due to build up of protein
- Loose clearness and sharpness of vision
- Congenital cataracts = born with it*
Glaucoma
- Increased fluid pressure in eye = loss of side vision and can lead to total blindness
- Pressure destroyed the optic nerve
- Avoid isometric exercises (increase pressure)
- Can happen in 1 or both eye
- Practice breathing patterns to reduce pressure buildup
Macular degeneration
- Gradual loss of vision caused by degeneration of macula
- Role = detailed central vision
- Death of rods and cones
- 10% of individuals between 66 to 74 years old
Retinal detachment
- Tear or hole in the retina
- Cause by injury : reversible when young and not big
- Cause by diabetic retinopathy : non-reversible
5 causes of blindness
- Diabetic retinopathy
- Cataracts
- Glaucoma
- Macular degeneration
- Retinal Detachment
Important things to remember (8)
- People with vision problem = not deaf
- Be direct
- Never grab a blind person’s arm
- Walk at a normal pace
- Don’t point or say over there, when giving direction
- Ask how much the person can see
- Describe surroundings
- Never distract or feed a service dog
Implications for exercise
- Precise verbal instruction
- Sight no required for many sports
- Good lighting
- Color contrast and bright color are important
- Eliminate noise