A process is provided for conducting an eye examination using a mobile device, the process comprising capturing a first image of an object using a camera of a mobile device set to a fixed focusing distance; determining, with reference to the first image, an absolute size of the object; capturing a second image of the object using the camera of the mobile device; determining, with reference to the second image, a distance from the mobile device to the object; providing an indication via the mobile device to move the mobile device relative to the object; and receiving input from the mobile device in response to the eye examination program.