Share on Facebook
Share on X
Share by Email
Share on Google Classroom
In Canada, as well as in many other countries, blindness is defined in such a way as to include persons who have some sight. The expression 6/60 (20/200) means that persons considered legally blind must come within 6 m of an object in order to see it, while persons considered sighted (i.e., 6/6 vision, 20/20) can see that same object from 60 m. Persons with a visual field of less than 20 degrees in diameter are also considered legally blind in Canada. This definition of blindness provides a practical model for organizations such as social-service agencies, educational, medical and government institutions.
The Canadian Council of the Blind reported that approximately 1.2 million Canadians were living with vision loss and blindness in 2019.
Canadian National Institute for the Blind
In Canada the largest agency serving Canadians who are blind and partially sighted is the Canadian National Institute for the Blind (CNIB). Founded in 1918, the CNIB is a national non-profit organization that served more than 12,000 individuals in the 2023-24 fiscal year. The objective of the CNIB is to "to change what it is to be blind through innovative programs and powerful advocacy that enable Canadians impacted by blindness to live the lives they choose." It operates a variety of rehabilitative, low-vision and social-service programs, as well as prevention of blindness and public-education programs. The CNIB also maintains and distributes research about vision loss, accessibility and related subjects.
Other organizations providing services to Canadians who are blind and living with vision loss include the Canadian Council of the Blind and the MAB-Mackay Rehabilitation Centre, which houses an elementary school. Other schools for the blind exist in Brantford, Ontario (W. Ross Macdonald School for the Blind) and in Longueuil, Quebec (École Jacques-Ouellette). Many groups like the Regroupement des aveugles et amblyopes du Québec, have played an important role in raising awareness of the rights of people living with blindness and vision loss.
Causes of Blindness
There are roughly four major causes of blindness and vision loss in Canada: macular degeneration, diabetic retinopathy, glaucoma and cataracts. The remaining causes are from various diseases, genetic predispositions and accidents.
Macular Degeneration
The macula is a small spot near the centre of the retina. This area is responsible for control of colour vision. If the macula deteriorates, the centre of the person's field of vision becomes blurred, and the ability to read is lost. Macular degeneration
seems to be part of the normal aging process.
Diabetic Retinopathy
The retina contains the light-sensitive nerve cells and fibres that transmit images to the brain. It is nourished by a network of blood vessels. In some diabetics, these fine blood vessels become more fragile and likely to bleed, causing loss of sight
(see Diabetes Mellitus).
Glaucoma
Glaucoma is an eye disease associated with abnormal pressure in the eye causing degeneration of the optic disk and may restrict in the field of vision.
Cataracts
A cataract is a clouding of the crystalline lens of the eye. The purpose of the lens is to bring the light rays entering the eye to a focus on the retina. When the lens becomes cloudy, the light rays cannot get through and the person loses sight. The
only treatment for a cataract is surgical removal of the lens and replacement by an artificial lens (see Ophthalmology).
There are many new surgical techniques that have been developed to help individuals with vision loss. Children with congenital cataracts are treated with surgery before they are a year old and are fitted with contact lenses. The laser is being used in some cases of diabetic retinopathy, glaucoma and macular degeneration. Many persons with partial sight can make use of various low vision aids.
Blindness and low vision should not restrict a person from living a full life. Many people who are blind have productive careers, attend school and universities and participate in recreational activities. On the other hand, there are many Canadians who are blind and partially sighted that require extensive rehabilitation and social services.
