How are the terms low vision, visually impaired and blind defined?

DO-IT Factsheet #85

According to the National Dissemination Center for Children with Disabilities (NICHCY) [1] the blanket term "visual impairment" includes low vision, partially sighted, legal blindness and total blindness. These terms are discussed below.

Low vision is used to describe a loss of visual acuity while retaining some vision. It applies to individuals with sight who are unable to read a newspaper at a normal distance of viewing, even with the aid of glasses or contact lenses. People with low vision often need adaptations in lighting and/or enlarged print to read something. There are two specific types of low vision:

Partially Sighted is usually used in educational contexts to describe a visual impairment that requires special education services. The partially sighted student meets the challenge of disability in much the same way as a totally blind student. Accommodations include the use of readers, audio taped texts, and raised-line drawings. The partially sighted student may be able to use large print books and a Closed-Circuit TV (CCTV) or other magnifying device. Some partially sighted students can take notes in class by printing very large with a felt tip pen or marker; others will tape record lectures for later use.

Legally Blind refers to people that have less than 20/200 vision in the better eye or a limited field of vision that is 20 degrees or less at its widest point. People who are legally blind may have some useful vision.

Totally Blind individuals need Braille, raised-line drawings, audio recordings, and/or other non-visual media as an accommodation for accessing the content of visually presented materials.

The descriptions above were compiled using the following resources.

The NICHCY publication Visual Impairments. [2]

The American Foundation for the Blind (AFB) [3] website.

The The National Federation of the Blind (NFB) [4] website.

Braille Plus, Inc.'s glossary [5] of definitions and terms related to braille, visual impairments and blindness.