Assessment of visual function using mobile Apps.

With the advances in smartphone and tablet screens, as well as their processing power and software, mobile apps have been developed reporting to assess visual function. This review assessed those mobile apps that have been evaluated in the scientific literature to measure visual acuity, reading metrics, contrast sensitivity, stereoacuity, colour vision and visual fields; these constitute just a small percentage of the total number of mobile apps reporting to measure these metrics available for tablets and smartphones. In general, research suggests that most of the mobile apps evaluated can accurately mimic most traditionally paper-based tests of visual function, benefitting from more even illumination from the backlit screen and aspects such as multiple tests and versions (to minimise memorisation) being available on the same equipment. Some also utilise the in-built device sensors to monitor aspects such as working distance and screen tilt. As the consequences of incorrectly recording visual function and using this to inform clinical management are serious, clinicians must check on the validity of a mobile app before adopting it as part of clinical practice.