GLOBAL CHALLENGES

Low-Cost Device Tests Vision with Cell Phone

Rebecca Kutzer-Rice | Date: 06-28-10 | Comments

MIT researchers have developed a handheld device that uses cell phones to test vision. The device could be especially useful in poor countries, where eye testing is not readily available.

Although glasses and contacts are commonplace in the developed world, uncorrected vision errors are a leading cause of blindness in poor countries, according to the World Health Organization. Such vision problems could be easily corrected if diagnostic methods were readily available, which, unfortunately, they are not. Researchers from MIT have developed a new method of vision testing that could revolutionize eye care throughout the world.

Current techniques of vision testing are inconvenient and expensive, consisting mostly of those large machines�called phoropters�with scores of lights and lenses. Another less common and more expensive machine is the aberrometer, which uses lasers to measure the movements of the eye. These machines are rare in developing countries, which lack financial resources and trained personnel.

Unlike traditional machines, a new device, called Near-Eye Tool for Refractive Assessment (NETRA), is handheld and inexpensive. It consists of a piece of plastic that clips onto a user�s cell phone, which must be loaded with special software. Inside the plastic is a lens, through which the user views parallel lines. He/she then uses the arrow keys to adjust the lines. The lines change position and the test is repeated for the other eye in a process that takes less than 2 minutes.

Ankit Mohan, one of the researchers, demonstrates the new device. The small vision test clips onto a cell phone to deliver accurate results in seconds (source: Andy Ryan, MIT).

Perhaps most promising about the device is its price. While phoropters can cost upward of $3,000 and aberrometers even more, the clip-on vision test can be manufactured for less than $2. The researchers predict that, in large quantities, it could be produced for just a few cents. Such a low price is vital for developing countries, which will also benefit from the machine�s ease of use. Untrained nurses and other workers will be able to quickly and easily test patients� vision. And while the device�s reliance on cell phones might seem unsuitable for poor nations, mobile devices are much more common than doctors in developing countries.

"Our device has the potential to make routine refractive eye exams simpler and cheaper, and, therefore, more accessible to millions of people in developing countries," states Manuel Oliveira, a visiting professor at MIT and one of the researchers on the project, according to the MIT press release.

Other researchers included professor Ramesh Raskar, Ph.D. candidate Vitor Pamplona and postdoctoral research associate Ankit Mohan. The team has applied for a patent on the device.