Visual impairment represents a continuum, from people with very poor vision, to people who can see light but no shapes, to people who have no perception of light at all. However, for general discussion it is useful to think of this population as representing two broad groups: those with low vision and those who are legally blind.
Low vision includes problems (after correction) such as dimness of vision, haziness, film over the eye, foggy vision, extreme near- or farsightedness, distortion of vision, spots before the eyes, color distortions, visual field defects, tunnel vision, no peripheral vision, abnormal sensitivity to light or glare, and night blindness.
Those who are legally blind may still retain some perception of shape and contrast or of light vs. dark (the ability to locate a light source), or they may be totally blind (having no awareness of environmental light).
Impact on Study:
- Student will not be able to work efficiently (at least) from visual displays and other visual output during lectures and for example seminar presentations.
- Student’s ability to read will be limited. Written operating instructions and other documentation may be unusable, and there can be difficulties in manipulation.
- Carrying out field or laboratory work may be virtually impossible and potentially dangerous.
How to Help:
- Seek alternate assessment in place of field or lab work.
- Many people with visual impairments still have some visual capability, so many of them can read with the assistance of magnifiers, bright lighting and glare reducers. Many such people with low vision are helped immensely by use of larger lettering, sans-serif typefaces, and high contrast coloring.
- Those with color blindness may have difficulty in those instances when information is color coded or where color pairs are chosen which result in poor ‘figure-ground’ contrast. For example, a student might have difficulty perceiving the words on paper from their background.
- Key coping strategies for people with more severe visual impairments include the use of braille and large raised lettering. Note, however, that braille is preferred by only 10% of blind people (normally those blind from early in life). Raised lettering must be large and is therefore better for indicating simple labels than for extensive text.