Smartphone-Based Screening for Visual Impairment in Kenyan School Children: A Cluster Randomised Controlled Trial

  • Childhood visual impairment is a major public health concern that requires effective screening and early intervention.

  • The study investigated the effectiveness of Peek school eye health, a smartphone-based sight test and referral system versus standard care.

  • It compared the performance of both the Snellen Tumbling-E card and the Peek Acuity test to a standard backlit EDTRS LogMAR visual acuity test chart. We did a cluster randomised controlled trial to compare the Peek school eye health system with standard school screening care, delivered by school teachers.

  • Sensitivity was similar for the Peek test and the standard test and specificity was lower.

  • Of the 295 eligible public primary schools in Trans Nzoia County, 50 schools were randomly selected and assigned to either the Peek group (n=25) or the standard group (n=25).

  • 10579 children were assessed for visual impairment in the Peek group and 10 284 children in the standard group.

  • Visual impairment was identified in 531 (5%) of 10 579 children in the Peek group and 366 (4%) of 10 284 children in the standard care group. The proportion of pupils identified as having visual impairment who attended their hospital referral was significantly higher in the Peek group  than in the standard group.

  • The Peek school eye health system increased adherence to hospital referral for visual impairment assessment compared with the standard approach among school children. This indicates the potential of this technology package to improve uptake of services and provide real-time visibility of health service delivery to help target resources.

Publication date

February 20, 2020


The Lancet Global Health

Sponsor Institution

Seeing is Believing, Operation Eyesight Universal, Queen Elizabeth Diamond Jubilee Trust, and Wellcome Trust


Hillary K Rono, Andrew Bastawrous,David Macleod, Emmanuel Wanjala, Gian Luca Di Tanna, Helen A Weiss, Matthew J Burton
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