‘Radar for the human eye’ Inexpensive hand-held device developed at MIT could detect cataracts even at the earliest stages. Cataracts are the leading cause of preventable blindness worldwide. But the standard test to detect the cloudy patches in the eye’s lens requires a $5,000 piece of equipment called a slit lamp, and a trained physician to interpret its results — two things that are often not available in rural and less-affluent parts of the world. But a team of MIT researchers has now developed a simple device that can clip onto an ordinary smartphone (or smart device such as an iPod) and provide a diagnosis of cataracts within a few minutes. Ramesh Raskar, the NEC Career Development Associate Professor of Computer and Communications and director of the MIT Media Lab’s Camera Culture group, says, “I like to think of this as a radar for the human eye.” Just as a weather radar beam sweeps across the sky to detect clouds, the new system — dubbed Catra — sweeps a beam of li...