In 2002, according to the World Health Organization (WHO) there were more than 161 million people in the world who were visually impaired. (Please note: WHO uses the term 'visual impairment' to include both 'low vision' and 'blindness.')

Of those, 37 million were blind and 124 million had low vision. This means for every blind person there are 3.4 people with low vision.

These figures do not include people with refractive error that can be corrected. Refractive disorders are conditions which prevent the eye from focusing light images on to the retina. Most refractive errors, which include myopia (nearsightedness), hyperopia (farsightedness), and astigmatism (a distorted curvature of the front surface of the eye), can be corrected to 20/20 i.e., normal vision, by wearing eyeglasses or contact lenses. See also our discussion of eye conditions on this web site.

The prevalence of eye diseases in the United States may be seen in this table from the National Eye Institute.[link opens in new window]