The 'Peek' app works to allow users to do eye exams with the help of smartphone technology. Researchers at the London School of Hygiene and Tropical Medicine developed the app to help those in developing areas keep their eyes healthy. As a result, they named their product the Portable Eye Examination Kit or Peek.
Peek is able to scan the eye to check for diseases as well as other problems. The app works to look for visual acuity, visual field, color vision and contrast sensitivity. All of this is done through functions of the Peek app.
The app does most of its testing through the smartphone's camera. Diseases are checked for by using a bright light to scan the eye. Other functions like vision checking can be done by holding the phone up at varying distances.