Low vision is the term used to describe significant visual impairment that can't be corrected fully with glasses, contact lenses, medication or eye surgery. People with low vision can't see well enough to drive or read most printed text unless they enlarge it
Many people imagine blindness as complete darkness. But that’s not entirely true. The term “blindness” covers a broad spectrum of visual disability, from when your sight is impaired enough to interfere with daily activities like reading, cooking or driving, up to total blindness.
Web Content Accessibility Guidelines (WCAG) 2.0 covers a wide range of recommendations for making Web content more accessible. Following these guidelines will make content accessible to a wider range of people with disabilities, including blindness and low vision, deafness and hearing loss, learning disabilities, cognitive limitations, limited movement, speech disabilities, photosensitivity and combinations of these. Following these guidelines will also often make your Web content more usable to users in general.