An app created by a Massey University researcher which simplifies the diagnosis of a common visual disorder is exploding in international popularity. Cerebral Visual Impairment is a condition where brain has trouble processing vision, affecting 3.4 per cent of children - that's one child in every classroom in New Zealand. The Austin Assessment app is a simple picture-matching game which can quickly pick up signs of CVI in children. It's been downloaded in 37 countries since it was launched in January. Its creator Nicola McDowell dealt with CVI as a teenager, and is hoping it's use will lead to formal diagnoses for the thousands of children who are currently falling through the cracks.