Eye chart number). The denominator indicates the distance in feet at which a person with normal vision could stand to correctly identify the same symbols identified by the person tested. For example, a visual acuity of 20/20 is considered normal. Numerous types of eye charts exist and are used in various situations. For example, the Snellen chart is designed for use at 6 meters or 20 feet, and is thus appropriate for testing distance vision. There is often also a need to test a subject's vision at near or occupational tasks (such as reading or computer use). For these situations, a Rosenbaum
International Resources for the Improvement of Sight International Resources for the Improvement of Sight International Resources for the Improvement of Sight (IRIS) is an International NGO that specializes in prevention of blindness and restoration of sight. It was founded in 1996 by Michele Claudel and John Stewart. It was initially founded to help people in Cambodia without access to eye care, it has since expanded to Nepal, Lao PDR and Sri Lanka. IRIS equips new eye clinics, strengthens existing ones, conducts eye screening, provides cataract surgery for poor people, primary eye care training for staff. IRIS has partnered with other NGOs to provide funding for services, such