The $1 foldable eye-screening kit is here / by Karen Frances Eng

The LV Prasad Eye Institute Center for Innovation in India has invented a foldable, mailable phoropter that could help prevent blindness in millions of children.

What’s a phoropter? You know that thing at the eye doctor’s that looks like a science-fiction insect robot mask? That. This impressive instrument is used to spot refractive error and measure our vision for corrective lenses, and typically costs several thousand dollars — which means that you have to go to an office with one installed to get your eyes checked. The problem is, everyone needs eye care — especially children, for whom eye health intervention at the right time can prevent irreversible vision loss. But while rates of blindness in wealthy countries are below 0.5 percent, blindness in poor people in the developing world exceeds 1 to 2 percent — much of which could be avoided with refractive error screening that’s simply not available to those populations.

Now the LVPEI Center for Innovation’s team of Indian ophthalmologists, led by inventor and TED Fellow Anthony Vipin Das, is taking eye screenings to communities in need with the Folding Foropter — a paper phoropter that requires no assembly, can be used by anyone anywhere to detect eye problems, and costs less than $1.50 to produce. As Vipin Das prepares to roll out the Folding Foropter to India and around the globe, he tells us more about how it works and why this simple device is so important.

 All photos courtesy of Folding Foropter

All photos courtesy of Folding Foropter

How did the Folding Foropter come about?

In 2013, my lab, the LVPEI Center for Innovation, started working on a simple device that would enable us to identify refractive error, the most common cause of avoidable blindness in children, to serve kids who live in rural areas with irregular access to eye care. Led by our colleague Veerendranath Peesala, we started by building something on a 3D printer. But then, inspired by TED Fellow Manu Prakash and his Foldscope origami microscope and paper centrifuge, we wondered, “Can we redesign an eye-diagnostic tool with paper products?”

Team members Dhruv Joshi and Sandeep Vempati built the phoropter with two cylinders of heavy paper that come folded and are assembled on site, like origami. Ashish Jain and Aadya Krishna Prasad, designers at the lab, worked extensively on user interaction and experience, making the Folding Foropter relevant to a global audience. The instructions for use are simple — and are presented as infographics, so specific language knowledge is not required.

After many iterations over the years, the final Folding Foropter costs less than $1.50 to produce and comes beautifully folded in an envelope. We went ahead and did a clinical study in more than 3,000 patients, and it is extremely accurate. In sum, we now have a proven, low-cost, foldable, in-your-pocket innovation that can actually help combat refractive error in children.

How does it work? Does it have lenses embedded in it?

The Paper Foropter has two lenses set at specific distances, embedded into the paper. It arrives completely flat. You open the envelope and find two squares and cylinders. You assemble the cylinders, slide one into the other, and an interlocking mechanism keeps the cylinders together. Once these are attached, the patient simply looks through the viewing lens. The patient closes one eye and focuses on the first clear image they’re able to see. The Foropter automatically measures what the refractive error is — which indicates whether the patient needs to see an eye doctor for follow-up. The process takes less than a minute, and anyone can test themselves.


Why is the Folding Foropter important?

Refractive error is one of the most common causes of school dropout in India. When children cannot see, they don’t know it and can’t describe it — they accept their own level of vision as normal. Until you test their vision, they won’t know the difference between crystal clear vision and what’s blurry.

Screenings are therefore necessary to diagnose eye problems, but for most remote villages, there are no screening facilities. The Folding Foropter is easy to take to such children, and because it’s simple to use and cheap to deploy, screenings can take place on a regular basis at schools and health centers. While full follow-up eye exams and prescriptions require clinics, the Foropter can at least do the crucial task of screening many children at once, identifying problems that can then be treated.

How does this differ from a device like TED Fellow Andrew Bastawrous’ Peek smartphone device?

What we do is complementary, in that we are both providing affordable and transportable eye diagnostics. In fact, I’ve sent Andrew a bunch of Folding Foropters for use in Botswana, where he’s working on a public/private partnership, and his team loves them!

But what the Folding Foropter does is different: Peek uses a smartphone and app to check visual acuity. It does not measure the eye refraction number. It is designed more for identification of vision impairment due to such causes such as cataract, glaucoma, macular degeneration and so on.

Folding Foropter, on the other hand, is for diagnosing refractive error in youngsters: people up to 20 to 25 years of age, predominantly. We focus on young people because that is the most important time to identify refractive error, which is the cause of more than 60% percent of avoidable blindness.