At a glance
Peek Vision, developed from research at the London School of Hygiene and Tropical Medicine, turns a smartphone into a validated vision testing tool that community health workers can carry into remote villages. In Kenya a randomized controlled trial found the system markedly increased the share of people who received the eye care they needed, and in Botswana it helped screen more than 120,000 schoolchildren with over 90 percent of those referred attending their appointments.
- Globally 596 million people live with distance vision impairment and 43 million are blind, with most affected in low and middle income countries
- Peek Acuity was validated in Kenya in 2015 as at least as accurate as conventional vision tests when used by non specialist health workers, and slightly faster
- A 2020 external review of 14 mobile vision tests rated Peek Acuity best for reproducibility and correlation with standard clinical methods
- A 2021 cluster randomized controlled trial in Kenya, published in The Lancet Digital Health, showed the Peek powered system improved access to eye health services
- Botswana used Peek to screen more than 120,000 schoolchildren, leading to a 2017 government commitment to screen every schoolchild and teacher nationally
Roughly 596 million people worldwide live with distance vision impairment, and 43 million of them are blind. The majority live in low and middle income countries where a simple pair of glasses or a routine cataract operation could transform their lives. The core problem is not treatment. It is finding the people who need it. In much of rural Africa there is one ophthalmologist for every million people or fewer, and vision testing equipment is locked inside urban clinics that villagers may never reach.
Peek Vision is a social enterprise that grew out of research at the London School of Hygiene and Tropical Medicine's International Centre for Eye Health. Its insight was simple: the most advanced sensor most communities already own is inside a cheap Android phone. Peek turns that phone into a clinical grade vision test that a community health worker with minimal training can administer anywhere, offline, in minutes. The app then uses smart triage to decide who needs specialist care and keeps contact with patients through automated messages until they actually receive it.
From a Research Project in Kenya to a Proven Tool
Peek began as a field research effort led by Andrew Bastawrous, an ophthalmologist who moved his family to Kitale in Kenya to run eye examinations across remote communities. Hauling conventional equipment between villages was slow and expensive, so his team built a phone based alternative. The result, Peek Acuity, measures how well a person can see using the phone screen, shaped letters, and the phone's own brightness controls, recording results automatically and eliminating the paper records that routinely got lost.
The validation work was rigorous. Research published in 2015 showed that Peek Acuity used by non specialist community health workers in Kenya was at least as accurate as conventional distance vision checks, and slightly quicker. In 2020 an external systematic review of 14 mobile visual acuity tests concluded that Peek Acuity had the best reproducibility and the strongest correlation with standard clinical testing of any app evaluated. Independent scrutiny like this is what separates genuinely useful health tools from app store optimism.
What the Randomized Trial Found
The defining evidence came in 2021. A cluster randomized controlled trial in Kenya, published in The Lancet Digital Health, compared a community eye health programme powered by Peek against a conventional programme. The Peek system did more than test vision. It geolocated every person screened, identified who needed onward referral, and sent targeted reminders so patients actually attended their appointments. Adherence to treatment is where most screening programmes collapse, and it is exactly where the software earns its keep.
The trial found the Peek powered system improved access to eye health services compared with the conventional approach. People identified with vision problems were more likely to be examined, referred appropriately, and to complete the journey to treatment. For a field crowded with pilot projects that never prove anything, a randomized trial published in a leading journal set Peek apart.
Botswana Went National
In 2016 the government of Botswana, working with local and international partners, used Peek to screen more than 120,000 schoolchildren for vision problems. Because the app tracked every child and sent reminders to families, over 90 percent of children referred for care attended their appointments, a figure most school screening programmes in wealthy countries would envy.
The pilot changed national policy. In 2017 Botswana's Ministry of Health and Wellness committed to a government funded programme to screen every schoolchild and teacher in the country and deliver eye care services to those who need them. A phone app designed in a London research lab had helped restructure how an entire country delivers childhood eye health.
Why the Design Choices Matter
Every detail of Peek reflects the realities of the places it serves. The app works fully offline, syncing data when connectivity appears. Tests are designed for people who cannot read, using shape recognition instead of letters. Results are logged automatically so nobody is lost to a missing paper record. Referral pathways are mapped so a health worker knows the nearest facility that can actually treat the condition found.
The system also gives programmes something they never had before: live data. Health ministries can see, in near real time, where vision loss is concentrated, which clinics are absorbing referrals, and where children are falling through the cracks. That turns eye care from an occasional charity mission into a managed, measurable health service.
The Bigger Picture
The World Health Organization estimates that uncorrected vision impairment costs the global economy hundreds of billions of dollars each year in lost productivity, while the cost of addressing it is a fraction of that. A child who cannot see the blackboard falls behind in school. An adult who cannot work loses income their family depends on. Most of this is preventable with a pair of glasses or a twenty minute cataract surgery.
Peek Vision shows how a modest piece of software, thoughtfully designed around the constraints of the communities it serves, can move the needle on a problem that affects hundreds of millions. It is not a moonshot. It is a phone, a health worker, and an app that refuses to let a person with treatable blindness stay invisible.
Common Questions
What is Peek Vision?
Peek Vision is a social enterprise that grew out of research at the London School of Hygiene and Tropical Medicine. Its apps turn smartphones into clinical grade vision testing tools that community health workers can use offline in remote communities, with smart triage, referral tracking, and automated patient reminders.
How accurate is the Peek Acuity app?
Research published in 2015 showed Peek Acuity used by non specialist health workers in Kenya was at least as accurate as conventional distance vision tests and slightly faster. A 2020 external systematic review of 14 mobile visual acuity tests rated Peek Acuity best for reproducibility and correlation with standard clinical methods.
What did the Kenya randomized trial show?
A cluster randomized controlled trial published in The Lancet Digital Health in 2021 compared a Peek powered community eye health programme with a conventional one in Kenya and found the Peek system improved access to eye health services, with more people examined, referred, and completing treatment.
How many children did Botswana screen with Peek?
In 2016 Botswana and its partners used Peek to screen more than 120,000 schoolchildren, with over 90 percent of referred children attending their appointments. The success led the Ministry of Health and Wellness to commit in 2017 to a national programme screening every schoolchild and teacher in the country.
How big is the global vision impairment problem?
Globally 596 million people live with distance vision impairment and 43 million are blind, with the majority affected living in low and middle income countries. Most cases are preventable or treatable with glasses or simple surgery, but people are never identified because testing capacity is concentrated in cities.
Sources: The Lancet Digital Health, cluster randomized controlled trial of an mHealth system on access to eye health services in Kenya (2021); London School of Hygiene and Tropical Medicine impact case studies; International Centre for Eye Health Peek Vision research; CBM and Peek Vision programme reports on Botswana school screening.
