The app keeps track of a user's location and the distance walked from home or a hotel, they said, and can even pinpoint the closest hotel should they find themselves too far from base to get home safely.
Night blindness, nyctalopia, afflicts millions who find it difficult or impossible to see in low-light conditions. That can put them at risk if darkness falls while they are in a strange city or even in their home town, the researchers said.
Writing in the International Journal of Mobile Learning and Organization, researchers in Karachi said the app could allow sufferers to safely leave their home knowing their phone is keeping track of their whereabouts and can calculate both the remaining daylight hours available and estimate how long it will take the person to reach their base before nightfall.
The application, geo-aware and knowing the time of sunset around the world, can access online mapping software which can offer the potentially vulnerable user with shortcuts back to their home or hotel, the researchers said.
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