Vision is one of the most important senses for human development. It is through vision that we acquire most of our knowledge about the world around us.
Visual impairment is defined as the partial or total loss of vision in one or both eyes that cannot be corrected or improved through medical treatment, surgery, contact lenses, or eyeglasses.
Any individual with reduced vision that cannot be corrected is considered a person with a visual impairment.
The World Health Organization uses the scale listed below for the following classifications of visual impairment.
- 20/30 to 20/60 is considered mild vision loss, or NEAR NORMAL VISION
- 20/70 to 20/160 is considered moderate low vision, MODERATE LOW VISION
- 20/200 to 20/400 is considered severe visual impairment, SEVERE LOW VISION
- 20/500 to 20/1000 is considered severe vision loss, SEVERE VISION LOSS
- A visual acuity of less than 20/1000 is considered near-total visual impairment, TOTAL OR NEAR-TOTAL BLINDNESS
- Any degree of vision is considered total visual impairment, TOTAL BLINDNESS
There are also levels of visual impairment based on loss of visual field ( loss of peripheral vision).
Low vision can be:
Congenital or acquired later in life.
Depending on the specific visual impairment and its severity, there are visual aids (magnifying glasses and telescopes), new technologies (electronic magnifiers and screen-reader software), filters, contrast enhancements, and lighting solutions designed to improve performance in specific tasks and enhance quality of life.
For all those who fit these criteria, I offer the words of Heumann (1998).
