The Folding Phoropter is a low-cost and easy-to-assemble eye test to quickly spot refractive errors, the largest cause of avoidable visual impairment in the developing world. Origami has been around since the 6th century. But the art of paper folding is now helping to bring cheap eye care to the developing world. The Folding Phoropter uses the ancient Japanese custom to spot vision disorder, putting the power of diagnosis into patients’ own hands. "The scenario right now is that there are a lot of people who do not have access to refractive error screening. And because they can’t do that [get tested] a lot of people go visually impaired," says Ashish Jain, industrial designer of L. V. Prasad Eye Institute in India’s Hyderabad institute. Poor eyesight affects an estimated 153 million people around the world, according to the World Health Organization. If diagnosed correctly it can be treated with glasses, contact lenses or refractive surgery.