Overcome the barriers of vision care in Africa using smartphones - PROJECT SUMMARY / ABSTRACT Worldwide, 671 million people have uncorrected refractive error out of which 161 million people have distance vision impairments due to uncorrected refractive error (URE). Distance vision impairment due to URE especially affects children and young adults, limiting their educational activities and social life. Although the prevalence of refractive error is lower, the prevalence of blindness due to URE in Africa is 6 times as that in high-income regions of the world. This indicates widespread disparities in access to eye care in Africa, which leads to long term negative effects. As a matter of fact, there are only 2.5 ophthalmologists per million population in Sub-Saharan Africa, against a global mean of about 32 ophthalmologists per million. Innovative community-based approaches are needed to tackle the increasing burden of providing the needed healthcare. In response to the grant opportunity to improve healthcare access to low and middle-income countries using mobile health, we propose to develop an AI-powered mobile application for measurement of refractive error and validate it by performing field tests in Ethiopia. With its relatively simple protocol, the app can allow lay people measure myopic refractive error using only a smartphone, without needing any phone attachments. Thus, it overcomes the main barriers of cost and accessibility. A recent study on this refraction app showed good consistency with clinical measurements of refraction in a multi-center study in the US and China. Given the bias and inaccuracies of AI algorithms in people of underrepresented African ethnicities, in the R21 phase, we will train a custom neural network on face datasets of African origin to make the current version of the app more suitable for dark-skinned Africans. We will validate the app measurements of refraction in Ethiopia by comparing it with standard clinical measurement, and also by determining the improvements in the visual acuity resulting from the app-based refractive correction. After the validation of the mobile technology for prescribing affordable eyeglasses in hospital settings, we will further evaluate community vision care programs in the R33 phase, including vision testing and dispensing of eyeglasses. Community volunteers will be trained to perform vision screening with the app and a field test will be performed in rural Ethiopia to determine the sensitivity and specificity of community-based myopia screening approach in real-world settings. With the mHealth solution, we are poised to make significant impact on the eye care in under-served Africa.