A photo of an eye using the smartphone app
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A smartphone app for eye tests could help world's poorest

15 August 2013 Last updated at 07:27 BST

More than 285 million people around the world are blind or visually impaired.

Most could be treated, but too often people are beyond the reach of even a basic eye examination.

Now researchers think new technology could be the solution to the problem, as James Gallagher has been finding out.