Blindness is a temporary or permanent medical condition perceived as loss of useful sight, which however is different than low vision. It can be due to many causes which result in a damage to any portion of the eye, the optic nerve or the area of the brain responsible for vision. A differentiation is usually made between the total blindness and legal blindness. Total blindness refers to the inability to see anything with either eye. Legal blindness is a level of vision loss that has been legally defined to determine eligibility for benefits. A person is diagnosed with (legal) blindness when has a visual acuity of 20/200 or less in the better eye with the best possible correction, and/or a visual field of 20 degrees or less.
Video explanations of blindness and legal blindness:
Examples of what people with blindness experience in everyday life:
Research, white papers and reports on all aspects of blindness and visual impairment:
- Raufi B, Rerati M, Zenuni X, Ajdari J, Ismaili F. Methods and Techniques of adaptive Web Accessibility for the blind and visually impaired. Procedia – Social and Behavioral Sciences, 195, 2015, pp.1999-2007.
- Duffy MA, Low vision and Legal Blindness Terms and Descriptions, URL: http://www.visionaware.org/info/your-eye-condition/eye-health/low-vision/low-vision-terms-and-descriptions/1235.
- Power C, Petrie H, Swallow D. Guidelines are only half of the story: accessibility problems encountered by blind users on the web. Proceedings of CHI’12, 2012, pp.433-442.
- International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10). Diseases of the eye and adnexa: visual disturbances and blindness (H53-H54). Url: http://apps.who.int/classifications/icd10/browse/2010/en#/H54.