A visual impairment occurs when the eye or eyes are unable to fully transmit a visual message to and from the visual cortex of the brain. A visual Impairment can be attributed to difficulties within the eye structure, eye movement, optic nerve or even the visual cortex of the brain. Therefore not all visual impairments are the same, although the umbrella term “visual impairment” may be used to describe generally the consequence of an eye condition or disorder.
As there are many different causes of visual impairment, the degree of impairment a child experiences can range from mild to severe (up to, and including, blindness). The degree of impairment will depend on:
The particular eye condition a child has;
What aspect of the visual system is affected (e.g. ability to detect light, shape, or colour; ability to see things at a distance, up close, or peripherally); and
How much correction is possible through glasses, contacts, medicine, or surgery.
The term “blindness” does not necessarily mean that a child cannot see anything at all. A child who is considered educationally blind may very well be able to see light, shapes, colours, and objects (albeit indistinctly). Having such residual vision can be a valuable asset for the child in learning, movement, and life
A pupil with a visual impairment will be able to do virtually all the activities and tasks that sighted pupil takes for granted, however a pupil with a visual impairment will need to learn to do them in a different way or using different tools or materials. Central to their learning will be touching, listening, smelling, tasting, moving, and using whatever vision they have.