The high resolution display screen on most mobile phones, has been combined with a small clip-on device costing as little as two dollars in quantity, to create a cheap instrument for doing eye tests.
A team led by Indian-American Associate Professor Ramesh Raskar at the Massachusetts Institute of Technology’s Media Lab has perfect NETRA – Near-Eye Tool for Refractive Assessment – a neat acronym which also makes the Hindi word for ‘eye’ . It is an interactive, portable, and inexpensive solution for estimating refractive errors in the human eye.
While expensive optical devices for automatic estimation of refractive correction – called aberrometers-- exist, NETRA simplifies the mechanism by putting the human subject in the loop. The solution combines inexpensive optical elements, interactive Graphical User Interfaces and computational reconstruction. The user looks into a small lens that comes with the clip-on and uses the phone’s arrow keys to make a set of parallel green and red lines just overlap. This is repeated 8 times with the lines at different angles for each eye. The p whole process takes two minutes after which the software kicks in to provide the prescription data. Postdoctoral research associate Ankit Mohan, says NETRA is different from other solutions because it has no moving parts; all the intelligence is in the software and can be produced very cheaply. In fact it grew out of another Media Lab project called Bocodes – tiny barcodes that pack a lot of information. Raskar’s wife, found she could see the bocode with one eye but not with the other – which set his thinking : Here is a way to see if there is something refractively wrong with your eyes!
“NETRA is like a thermometer for the eye, and just easy to use”, says co researcher and lead author, Vitor Pamplona.
Do see our video on the home page for a brief period, which catches all these researchers live and talking about NETRA.
Link to full paper: Citation: Vitor F. Pamplona, Ankit Mohan, Manuel M. Oliveira, Ramesh Raskar. NETRA: Interactive Display for Estimating Refractive Errors and Focal Range. Proc. of SIGGRAPH 2010 (ACM Transactions on Graphics 29, 3), 2010.
June 27 2010