MIT develops smartphone-based eye exam

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MIT’s Media Lab is working on a project that could help people in poor countries get their eyes tested using a cellphone.

MIT’s Media Lab is working on a project that could help people in poor countries get their eyes tested using a cell phone.

When you go to get your eyes checked there are two ways the optometrist will measure whether you need prescription eyeglasses. They will either use a phoropter, where the patient tries to read a standard eye chart while different lenses swing into place in front of each eye in various combinations. The other system is called an aberrometer which uses laser technology to evaluate the eye.

Both of these are cost prohibitive in impoverished areas of Africa and elsewhere in the developing world. The World Health Organization suggests there are two billion people with refractive errors such as nearsightedness, farsightedness and astigmatism. Uncorrected refractive errors are the world’s second-highest cause of blindness.

Media Lab student Vitor Pamplona, along with Ramesh Raskar and Manuel Oliveira, post-doc Ankit Mohan and two professors at the Media Lab have developed a system for prescribing eyeglasses that only requires a smartphone and a simple plastic lens attachment that costs around $2.

Called NETRA, or Near-Eye Tool for Refractive Assessment, a patient peers into the lens attachment connected to a smartphone, loaded with the testing app. Patients will then see parallel red and green lines and use arrow keys on the phone to adjust those lines until they overlap. After about two minutes the app provides an eyeglass prescription.

Anchor Marco Werman visited the MediaLab to speak with the researchers and get his eyes checked using NETRA.

• More on MIT’s NETRA technology
• In The World: Easy on the eyes
• Video: BBC ‘Smart vision for mobile phones in the developing world’

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MARCO WERMAN: I’m Marco Werman and this is The World, a co-production of the BBC World Service, PRI and WGBH Boston. If it weren’t for my reading glasses, the words on this page would just appear as blurs to me. Lucky for me, I live in a part of the globe where correcting my vision is really quite simple. Here in the US I have relatively easy access to an eye doctor who can diagnose my vision needs. And I can readily purchase the eyeglasses I require to see properly. Millions of people around the world aren’t so lucky. Access to doctors is limited for the poor living in developing nations. Which is why a new technology developed at the Massachusetts Institute of Technology caught my attention. I’m at MIT’s media lab, which has come up with an innovative way of testing your vision. Ramesh Raskar is the head of the project and explain what you have actually developed here Ramesh.

RAMESH RASKAR:  We have a clip-on eyepiece that would go on top of a display for a cell phone. A user would look through this eyepiece, interactively align some patterns, and the number of clicks it would take would indicate to us what your nearsightedness, farsightedness, and a stigmatism is.

WERMAN:  What is the technology in a mobile phone that allows you to piggyback with this technology for testing eyes?

RASKAR: The interesting aspect of today’s cell phones is their [SOUNDS LIKE] pixel pitch has come down to 30 micrometers. Very tiny, very high resolution. And that’s because people want to watch HD movies. To the cell phones can start performing tasks that are comparable to the highest end scientific instruments.

WERMAN: Just to describe this. I mean it looks – the little eyepiece is about two inches long, it’s a square piece of white plastic and at the end there’s a rubber eyecup that I suppose I’m going to look into right?

RASKAR: That’s right.

WERMAN: So when I look through this eyepiece, basically at the screen of the cell phone, what am I seeing and what am I doing so I know what’s wrong with me?

RASKAR: You would look through this eyepiece and interactively align some patterns using the keyboard on your phone basically bringing the lines of the pattern closer and further away and when they appear to be aligned for you, you’ll stop and hit calculate, and that will give you the prescription or the data for your prescription.

WERMAN: So, you’ve got your device. Obviously you need a cell phone. Is that it for taking your own vision test?

RASKAR: Basically you need a cell phone, the clip-on eyepiece, and the software from the app store that you’ll take from our website.

WERMAN:  Will any cell phone work? I mean people in developing countries who don’t have a smartphone, are they out of luck?

RASKAR: Currently it’s designed to work with very high resolution displays. And currently it’s also working on smartphone because on a smartphone allows you to run our software. But in theory it could run on a whole range of mobile phones. So, I don’t know if you want to try it.

WERMAN: Yeah. So what are the buttons I’m going to be using… [OVERLAPPING]

RASKAR: You’ll be using just these buttons here. This to go down and this one to go up. And what you will do is click just once and then again let your eyes relax.

WERMAN: I’m looking through the eyepiece and I see…

RASKAR: Don’t do anything yet.

WERMAN: No, I’m not clicking on anything. I’m seeing the little circles of green and red.

RASKAR: Now, are the red and the green lights touching each other?

WERMAN:  No, they are not.

RASKAR: And so if you click once, they might come into alignment.

WERMAN: The two lines are now in alignment

RASKAR: Okay, and then you can stop.

WERMAN: Okay.

RASKAR: Looks like you have just a minus 1 or minus 1.5 error in your… [OVERLAPPING]

WERMAN: One point. Well, it doesn’t say on here, but I can assure you these are 1.25 diopters.

RASKAR: Beautiful.

WERMAN:  Yeah. So, I’m really impressed by this but, I got to say, then the problem is out there and in the developing world, I mean poor people are going to have to fix those problems. Are you prepared for this kind of onslaught of visual problems and what the MIT media lab has to kind of do to help people’s vision out?

RASKAR: We do research here, but the problem is very widespread. I mean 2 billion people worldwide have a refractive error, but unfortunately about half a billion people worldwide have uncorrected refractive error that affects their livelihood and leads to illiteracy and poverty as so on. And although some solutions have emerged that allow you to create very cheap glasses, surprisingly there is no easy solution for measuring the error. So, we think if we can create this, basically a thermometer for your vision, then we might be able to distribute this very cheap clip-on eyepiece and give away our software for free so that many NGO’s can use our device for doing eye tests. The glasses can be delivered later on or they could be a [SOUNDS LIKE] kiosk model or the NGO may come up with their own solutions on how to go back and deliver those glasses.

WERMAN: Now, we’re about to hear a story from Kenya where a cell service price wars dropping rates to new low levels. You find Masai shepherds with their cattle and the guy’s got a cell phone around his neck. I presume you’re anticipating the continued penetration and growth of cell phones around the world, especially the developing world, for this product to have serious relevance.

RASKAR: Certainly. I come from India and a huge percent of the population lives below a dollar a day and still over 60% of the population has a cell phone. People who barely make a dollar a day have a cell phone and it’s just becoming a very bigger part of our life. And so solutions that are based on cell phone just naturally can piggyback that penetration and provide services, in this case for health in very remote areas.

WERMAN: Ramesh thanks very much for demonstrating this unique innovation.

RASKAR: Thank you.

WERMAN: Ramesh Raskar is project director of the Near-Eye Tool for Refractive Assessment project at MIT. You can see me getting my cell phone eye test and find out more about the MIT media lab project at TheWorld.org.

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