Smartphone app Guides Night Blindness Sufferers

A new app keeps track of location and distance walked from a home or a hotel, warning sufferers of night blindness (nyctalopia), when they are likely to be caught out after dark.

Researchers at the Federal Urdu University of Arts, Science and Technology (Karachi, Pakistan) developed the smartphone app to allow nyctalopia victims to safely leave their home knowing that their phone is keeping track of their whereabouts, calculating both the remaining daylight hours available as well as estimating how long it will take the person to reach their base before nightfall.

The application is geo-aware, knowing the time of sunset around the world, as well as having access to online mapping software, which can offer the potentially vulnerable user with shortcuts back to their base. The app also has an added benefit of being able to locate nearby hotels, should the user need to reach one before darkness falls. The study describing the new app was published in the July 2013 issue of the International Journal Mobile Learning and Organization.

“Night blindness afflicts millions and may be present at birth as a genetic disease, arise in childhood through malnutrition or injury, or be a symptom of numerous eye diseases,” said lead author Kamran Ahsan, PhD. “Sufferers find it difficult or impossible to see in low-light conditions and so can be very much at-risk if darkness falls while they are in a strange city or even in their home town. Of course, many people with nyctalopia never venture from their home environment because of their disability.”

The most common cause of nyctalopia is retinitis pigmentosa, a genetic disorder in which the rod cells in the retina gradually lose their ability to respond to the light. Patients suffering from this condition have progressive nyctalopia, and eventually their daytime vision may also be affected. Other causes include X-linked congenital stationary night blindness, in which the rod cells either do not work at all, or work very little, and night blindness caused by a deficiency of retinol (vitamin A), found in fish oils, liver, and dairy products.

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Federal Urdu University of Arts, Science and Technology