iPhone eye test spots vision problems cheaply

PEER into a smartphone, and all will become clear. Smart Vision Labs, a start-up in New York City, wants to make it easier to diagnose vision problems in developing countries with an iPhone camera add-on.

The World Health Organization estimates that 246 million people have poor vision. Of these, about 90 per cent live in low-income areas without good access to healthcare or expensive diagnostic machines.

To solve this problem Smart Vision Labs has combined two tools often used for eye tests into a single inexpensive and portable device. The first tool, an autorefractor, calculates whether someone is short-sighted or long-sighted, and to what extent, by measuring the size and shape of their eye. The second, an aberrometer, looks for distortions in how light reflects off the eye, which could indicate rarer problems such as double vision.