Researchers at the Massachusetts Institute of Technology are working on an inexpensive way to use smartphones to detect early-stage cataracts, the clouding of the eye's lens that is the leading cause of blindness worldwide. Cataracts are the number one cause of preventable blindness in India.
Developed by Media Lab Camera Culture group director Ramesh Raskar and colleagues, the Catra system is made of off-the-shelf components. Users have to peer through an eyepiece that slides onto a smartphone or other smart devices such as an iPod Touch, and view lines displayed on the screen.
When the lines appear cloudy, the user has to press a button to get the device to scan the lens of the eye to create a map of the areas that appear cloudy because of proteins clumping together.
Catra produces a diagnosis of cataracts in minutes by identifying the position, size, shape and density of the clouds. It's been tested on 22 people. The system even identified one case of cataract that had not been picked up in an eye test at a ophthalmology clinic a few months ago.
Catra is expected to give a boost to early cataract diagnosis in developing countries where few people have access to the expensive slit lamps and clinicians used to diagnose the disorder. Earlier detection of cataracts gets better results after surgery.
The research follows Raskar's group's work on NETRA, a smartphone eye test for prescriptions that is low-cost and quick.