Abstract: A mobile device and a method for testing an individual's vision are provided, the mobile device including a screen for displaying at least one test pattern, such as a smartphone or a tablet computer. A test of the individual's vision is performed using the test pattern displayed on the screen of the mobile device, in particular for testing visual acuity, contrast sensitivity and/or visual disturbances. Further, a parameter influencing the test result is evaluated before and/or during performing the test. The parameter includes at least one of the distance between the eye of the individual and the screen; the brightness at which the test pattern is displayed; and the ambient luminosity.