A letter “E” is shown on the screen. It changes in orientation and size, each size being a different vision level.
The patient points in the direction of the E and the tester records this response by swiping on the phone screen in the same direction the patient pointed.
There is no need for the tester to look at the screen – the app works out if the answer was right or wrong.
The app calculates the vision score and presents at the end of the test and links to a simulation show what the visual world looks like for the person just tested.
36 million people worldwide are blind. Four in five of them could keep their sight with simple surgery or treatment. Millions more can't see clearly, yet need no more than a simple pair of glasses. We won't stop until everyone has been linked to the treatment and services they need.