Cours 4 : Blindness & Visual Impairments Flashcards
Do you have to be totally blind to be considered as visually impaired?
No
Do you have any experience with someone who basically a visual impairment?
Yes
What is the difference between visual acuity vs visual field?
Visual acuity measures the morphoscopic sense, or the capacity if the eye to distinguish details through distance vision and near vision
Visual field measures te sense of space and the extent of the visual field
What is being legally blind - legal blindness?
20/200 or less with the best correction (acuity ~ 10% or visual field less than 10degrees (tunnel vision)
What is total blindness?
Inability to recognize a string light shown directly into the eye.
More than 80% have residual vision and less than 20% are totally blind
What is the classification of B1 and it’s description?
From total blindness to very low residual vision
Description :
- 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
- Do sports like swimming, judo and wrestling independently. Track event with a guide
What is the classification of B2 and it’s description?
Low residual vision
Description :
- Ability to recognize the shape of hand up to a visual acuity of 2/60 and/or a limitation of field of vision of 5 degrees
- Can do many activities independently with the sunlight / bright indoor light
What is the classification of B3 and it’s description?
Better residual vision
Description :
- 2/60 to 6/60 (20/200) vision and/or field of vision between 5 to 20 degrees
- Do not use guides for most activities (except high-risk activities ; ex : rock climbing, downhill skiing, etc).
Where is the blind when they do blind alpine skiing with a guide at the paralympics?
At the back
Where is the blind at the recreational skiing?
99 % of blind people are guided from behind by their sighted guide
Where is the blind at the ski racing ?
Almost 100% of skiers are guided from the front
What is the incidence in QC for blindness?
8000 people in Quebec are legally blind
50% are over 65 years old
10% are under 20 years old
What are the realities of vision loss?
Only 1/3 of adults with vision loss are employed
3X more likely to experience depression
Greater risk of social isolation
practice how to explain by being blind folded (internships in KCEP and AT)
What are the causes of blindness?
A. Diabetic retinopathy
B. Cataracts
C. Glaucoma
D. Macular degeneration
E. Retinal detachment
What is the macula for?
It’s for central vision
What happens when light comes into the lens?
Light goes through and then hits the retina. Retina cells convert light into neural impulses (photoreceptors) - cônes + bâtonnets and its transmitted to the optic nerve.
Blood vessels supply nutrients to eye structures including retinal cells.
Diabetes can affect vision if the blood vessels burst! (Better control it!!)
What is diabetic retinopathy?
Leading cause fo blindness between the ages of 20 and 65 years old
Complication of diabetes and leading cause of blindness. It occurs when diabetes damages the tiny blood vessels inside the retina (damages = not reversible)
What are cataracts?
+++ in senior citizens
A cataract is a clouding of the natural lens, the part of the eye responsible for focusing light and producing clear, sharp images
What is glaucoma?
This disease increases the fluid pressure inside the eye, leading to loss of side vision and eventually total blindness
The increased pressure destroys the optic nerve
Why you should avoid isometric exercises?
The overall pressure of the body will be high, especially when there’s an older population
To release the pressure, you can drill into your eye ball and they can give you eye drops.
What is macular degeneration?
Macular degeneration is the gradual loss of vision caused by the degeneration of the macula, which is small, circular membrane at the center of the retina (role = detailed central vision)
Occurs in +- 10% of individuals 66 to 74 years of age
What is the role of macula?
Detailed central vision ex: reading
What is retinal detachment?
Retinal detachment is associated with a tear or a hole in the retina of the eye
Can be caused by injuries or diabetic retinopathy
What are things to remember?
People with vision problems are not deaf
When offering assistance, be direct
Never grab a blind person’s arm. Permit him/her to take your arm
When guiding, walk at a normal pace
When giving directions, dont point or say over there
If tou are not sure how much the person can see, ask
Describe the surroundings
Never distract or feed a dog guiding a blind or visually impaired person
