Use blind only when the person has complete loss of sight and legally blind when the person has almost complete loss of sight. Other terms also may be acceptable. It is best to ask your sources what terms they prefer and take that into consideration. Commonly used terms include: limited vision, low vision, and visually impaired (but similar to the term hearing impaired, some may object to it because it describes the condition in terms of a deficiency).
(Source: Disability Language Style Guide, National Center on Disability and Journalism)