Children’s eye care transformed using smartphone vision testing, study finds
© Peek Vision

Children’s eye care transformed using smartphone vision testing, study finds

A study, supported by The Queen Elizabeth Diamond Jubilee Trust, has found that schoolchildren in Kenya are twice as likely to attend crucial follow-up eyesight appointments if tested using Peek’s smartphone-based vision testing app compared with traditional paper methods.

Millions of children around the world live with poor vision, especially in low-income countries. They are held back in school and their future prospects hindered, when often all they need is a pair of glasses to be able to see. The research, which today has been published in The Lancet Global Health, compared the outcomes of over 20,000 school children across 50 schools in Trans Nzoia County, Kenya. 

Led by Ophthalmologist, Commonwealth Eye Health Consortium PhD student and protagonist of Trust film Double Joy, Dr Hillary Rono, for the London School of Hygiene & Tropical Medicine, in partnership with the Kenyan Ministry of Health, randomly assigned participating schools to receive either Peek School Eye Health System screening or standard screening using conventional paper eye charts. The Peek School Eye Health System allowed non-eye care workers, in this case teachers, to perform vision tests using a smartphone app. The results of the test were shown as an image via a simulation tool comparing what they saw to clear vision. These images were then printed out with details of their appointments to take home to their parents or carers, who also receive text-message reminders about their appointment. In the standard group, schoolchildren were given the conventional paper-based vision test, also by teachers, and received a written hospital referral letter.

The study found that over half (54%) of the children screened using the Peek School Eye Health System who were referred for follow-up attended the appointment, compared with only 22% of those tested using conventional methods.

Dr Hillary Rono explained his motivation behind the study: 

“I live and work in an area of Kenya where specialist eye health workers are few and far between. It’s vital that we can use the resources we have as efficiently as possible, which is where the idea for school eye health screening came from – instead of sending highly qualified ophthalmic nurses to schools, what if the schools could accurately identify which children need further examination? 

Today, more than 80% of people in Kenya own a mobile phone – more than have access to clean water - so it makes sense to use this technology to improve the efficiency of our health care system. Many young people don’t receive treatment or a pair of glasses which would allow them to see properly – something which could transform their lives, education and career prospects.

In this study – which is the first of its kind - we found that the Peek school eye health system substantially increased the proportion of children who attended their hospital appointment.”

Still in its early stages, the team are addressing areas of the screening programme that could be improved, such as refining the testing algorithms.

The Trust has supported the development of Peek since 2014 and provided a scholarship to Dr Rono for his PhD through its Fellowships, Research and Technology Initiative which aims to strengthen eye care across the Commonwealth and provide access to quality eye care to all those who need it.

Dr Andrew Cooper, Director of Programmes at The Trust, said,

“The publication of this study in the Lancet Global Health has exciting implications for the future of eye health. Since its inception, the Trust has believed in Peek’s potential to revolutionise eye care and ensure that all people, in even the remotest of settings, are not held back in life due to vision problems that can be treated or avoided.

Over 19 million children are affected by poor vision, and in settings such as this in Trans Nzoia County, Kenya, there are very few eye health professionals to screen, identify and treat common vision problems. The improved efficiency, accuracy and accessibility that the Peek School Screening System brings, as evidenced in this study, will help unlock the potential of the countless lives across Kenya, the Commonwealth and beyond.”

The screening programme has now expanded to cover the whole of the Trans Nzoia region and will soon expand to other regions of Kenya in partnership with the Ministries of Health and Education.


Hillary Rono, Andrew Bastawrous, David Macleod, Emmanuel Wanjala, GianLuca DiTanna, Helen Weiss, Matthew Burton. Smartphone-based visual impairment screening in Kenyan school children: a cluster randomised trial. Lancet Global Health. DOI: