The Nature and Degree of Vision Impairment
Educators will be better able to make adjustments to accommodate the student’s learning process by developing an understanding of the nature and degree of the vision loss and the educational implications of this loss.
Vision impairment refers to a significant loss of vision in both eyes, which cannot be corrected with glasses. The degree of loss may vary significantly, which means that each student with low vision or blindness needs individual adjustments to learn most effectively.
There are two main categories of vision impairment:
- low vision – people with low vision may also also be referred to as partially sighted and
- blind – no light perception
The majority of students with vision impairments have low vision, which means they are print users but may require special equipment and materials. These students should be encouraged to use their residual vision in their educational program as much as possible.
Students who are described as legally blind usually have some vision. The term legally blind is used to indicate entitlement to important government and private agency services. The term legally blind also includes people who are totally blind.
Vision impairments are also classified as:
- congenital – vision loss which is present at birth or
- adventitious – vision loss later in life as a result of a degenerative condition, illness or accident
The age of onset and level of development before sight loss occurs are critical factors in the student’s ability to acquire skills and concepts.
It is important to be aware that although two children with vision impairments may be assessed as having the same visual acuity, they may function and learn in very different ways.
Vision may fluctuate or may be temporarily influenced by such factors as vision fatigue, lighting and/or glare.
An understanding of the type of vision impairment is certainly important, but generalisations about the student’s visual functioning cannot be made solely on the basis of the diagnosed eye condition.
For further information see Vision and Vision Impairment.