Visual impairment or blindness is a sensory disability where the level of impairment varies greatly and can result from a number of diseases, disorders and injuries.

The Department of Social, Community and Family affairs defines 'blind' as seeing at six metres what other people see at 60 metres. Although this definition covers those who have no vision whatsoever, those considered legally blind can also include people with a degree of vision. Indeed, the National Council for the Blind has found that 80% of those registered as blind have usable residual vision, i.e. vision remaining after disease, accident or as a result of aging.

Assistive technology, such as computers or Braille n' Speak can put visually impaired people on an equal footing with able-bodied people.

The NCBI provides information, advice and support from a nationwide network of rehabilitation, mobility and community resource workers as well as trainers in the use of adaptive technology. The council offers services to people in their own homes or locality as appropriate, and to this end runs regional resource centres and low vision services throughout the country. Services administered by community-based staff include mobility and daily living skills training, rehabilitation, peer counselling and family therapy.

The NCBI also operates an employment support unit and jobseeking skills programme. It offers advice to both employers and employees on application procedures, interviews and career advancement, as well as advice on what adaptations can be made to assist a person with a vision impairment in the workplace and the grants that are available.