An App That Is Transforming Vision Tests

It was the beginning of a long, difficult day in July 2012. I had left my home in Kenya before the sun rose that morning. My team and I had traveled for hours along dark, dusty roads until they gave out, and we rumbled across fields to reach the small village where we were setting up a temporary eye clinic.

As we approached the church hall where the clinic was being held, we were greeted by scores of people, young and old, patiently waiting to be seen by us—a traveling eye care team—despite the fact that it wasn’t yet 8 a.m. I knew that many of these people had traveled many miles to be there and, as was often the case, we had our work cut out for us to set up the clinic quickly so we could start examining them.

One of the people in that queue, Mama Amanda, a grandmother clutching a long stick in her right arm, with a grandchild under her left, had been living with blindness for eight years. Her condition, cataracts, was completely treatable with a 10-minute operation, yet Mama Amanda had never had an eye test before.

Most people will have had their eyes checked by an optometrist or doctor at some point in their life. If you’re based in the Global North, you’ve probably had your vision and eye health checked in a comfortable, air-conditioned room full of illuminated letter charts, machines, and gadgets. 

Vision loss is one of the world’s most common health issues. Almost everyone will need eye care in their lifetime, and a staggering 1.1 billion people worldwide have vision loss that could be treated today. Yet most of them will never have had their vision checked. In fact, more than 90% of people who need eye care can’t access it—people like those waiting in the orderly line that I watched get longer by the minute on that long, hot day in 2012.

We started unpacking our bulky hospital equipment to set up the clinic. As I was carrying one of the larger machines from the minibus, I heard a bang from inside the hall. I rushed in to find Cosmas, a brilliant young IT expert on our team, peering at a blown fuse. The power supply to the hall had shorted and we were facing disaster—without electricity, none of our equipment would work, and we’d leave the long line of people outside disappointed.

Cosmas suggested we all go and wait outside so he could think about a workaround. As I took a quick walk around the village to clear my head, my thoughts were broken by a familiar sound—the overly loud ringtone of a Nokia mobile phone. It made me wonder that if a village like this with no reliable electricity supply or running water has a perfect mobile signal, was there some way that all these people disconnected from eye health care could be reached by that signal too?

There was another bang as Cosmas managed one of his genius fixes to get the power supply back up and running. We got the clinic set up by midmorning and were able to start testing and treating people.

While examining Mama Amanda, I confirmed that she had cataracts we could treat. The emotion it stirred in her, a sharp blend of despair and hope, was one I have come to know too well now. Despair because the cure had been there all along, yet she had spent years in darkness, alone and frightened. Her world had shrunk to the walls of her small home, and her granddaughter had become her eyes, her guide, her voice in the market, her link to the world—at the cost to her granddaughter’s childhood and schooling. And then hope, fierce and immediate, because maybe tomorrow everything could change; her story did not have to end the way it had begun.

The thought planted in my mind that morning—that maybe mobile phones could be the key to better eye health—began to grow. People like Mama Amanda were everywhere, invisible. Yet technology and connectivity were in unlikely places and might change the future. Working with my team in Kenya and a host of incredible collaborators from across the world, we began to test different ways that smartphones—just becoming popular at that time—could help address the vast need for eye health care in countries like Kenya.

After a few false starts, we developed a proof of concept for an app we eventually called Peek Acuity. The idea was simple: Peek Acuity replicates the illuminated chart with letters that anyone who has ever had their eyes tested will be familiar with. The difference is that with just a few minutes of training, anyone can use the app to accurately check another person’s vision. And to work it only requires a standard smartphone—not the bulky, unreliable equipment we had to grapple with that day in Kenya.

Peek Acuity is now used in more than 100 countries, making it an example of reverse innovation—the concept where something developed for use in low-resource settings becomes widely available in more economically developed nations too, benefiting everyone. In fact, eye health is a real hotbed of reverse innovation. When I started working in global public eye health 20 years ago, I was hugely inspired by organizations like Aravind Eye Hospital in India, which developed a high-volume, low-cost way of performing cataract surgery that has now literally saved the sight of millions of people worldwide—and does so at a volume and quality comparable to the whole of the British National Health Service, at a fraction of the cost.

In other areas of health, reverse innovation has brought new approaches and technologies that have saved millions of lives. For example, oral rehydration therapy to treat life-threatening dehydration caused by diarrhea was originally developed in Bangladesh, and is now a standard of care worldwide that’s estimated to have saved more than 70 million lives since its introduction in the late 1970s. Another example, the Cardiopad, a tablet device that can accurately read a patient’s heart rates and send them to a remote cardiologist for analysis, was invented in Cameroon and is now being used in outpost towns in western Europe.

The power of reverse innovation lies in its ability to focus on the solution, rather than getting distracted by how to get there. For example, when we were developing Peek, one of the problems we needed to solve was ensuring that vision tests were done at a standard distance—usually 2 meters (about 7 feet)—between the person using the smartphone and the person being tested.

We were pretty sure that we could use the smartphone’s front-facing camera to triangulate the distance of the person being tested and to flag the tester to adjust their distance if needed. Yet, after months of development, when we finally took the app out to be tested in situ, it was a failure, and the triangulation element was really erratic. However, a different tactic we tested concurrently proved to be 100% reliable, portable, and extremely cheap: a precut piece of string, measured out to exactly 2 meters. To this day, that’s how our users working in large-scale eye health programs ensure an accurate testing distance. The string is cheap, easy, and it works every time.

In the last 20 years, medical innovation has exploded. In my early days practicing as an eye surgeon in the U.K.’s National Health Service, I could barely keep up with all the new techniques, technologies, and gadgets coming on the market. Yet, at the same time, I had a nagging thought at the back of my mind—with all of this sophisticated technology, there remained millions of people who couldn’t access even basic eye care. 

For more than 90% of the billion-plus people worldwide with eye issues, all they require is a pair of glasses—a 700-year-old invention—or cataract surgery, which was first recorded in historical documents from around 800 BCE. Incidentally, those ancient references to cataract surgeries are from India—a hotbed of ophthalmological innovation even then—and Egypt, where my parents were born.

In recent years, there’s been a huge amount of excitement about how artificial intelligence and other cutting-edge technologies can create even more innovative ways to treat eye health. Yet I still find myself returning to a simple point: Technology alone doesn’t solve eye health problems, people do. Perhaps that’s why reverse innovation is such an important concept in health today—and one that deserves more attention. In constrained circumstances, you’ll always come up with the solution that works for the people it’s designed to serve.

While Peek Acuity now is being used in over 100 countries, we soon realized an eye test alone would not be enough. We’ve gone on to build and integrate the app into a wider system that helps nongovernmental organizations, governments, and eye hospitals in the Global South understand where patients are needing treatment but are not accessing it, allowing them to put their scarce resources where they’re really needed. The original eye test app also remains available—downloadable for anyone with an Android device. And we know that it’s being used in all sorts of places, not just in the Global South, but also in the U.K.’s National Health Service and across the U.S., where parents check their children’s vision and get them to the eye care they need.

Today, Peek works in partnership with eye health providers in 12 countries and our vision screening and data insights platform has helped more than 1.5 million people reach care. Over 100,000 people a week now receive an eye test using Peek, and we’ve cumulatively reached over 15 million people, two-thirds of them in the last two years, thanks to our incredible partners in eye health and a small cohort of forward-thinking philanthropists. 

But that’s just a drop in the ocean of need. Without major changes, close to 1.8 billion people are expected to be living with vision loss by 2050. We need to do so much more, and that’s why we continue to explore new partnerships and ways of making eye health sustainable, powered by technology but always led by the people who use and benefit from our tools.

We didn’t set out to create a reverse innovation that long, hot day in Kenya. Then, as now, my team and I were motivated by a single, simple idea: that everyone should have access to vision and eye health. 

For the people Peek reaches the change is more than sight. It’s the return of something no chart can measure. For Mama Amanda, it wasn’t just that the world came back into focus, it was that her life came back to her. Independence. Dignity. The quiet pride of moving through her day without leaning on another’s arm. Her granddaughter got back to school, her own dreams no longer on hold. And Mama Amanda was once again where her spirit belonged: in the kitchen with her favorite recipes, in the garden where her hands knew every stem, and in the heart of her family, giving more than she received.

This is what can happen when technology and compassion walk hand in hand.

Andrew Bastawrous is a professor of global eye health at the London School of Hygiene & Tropical Medicine, and co-founder of Peek Vision, which is solely owned by the Peek Vision Foundation, a registered U.K. charity.

The Takeaway