A mobile device and a method for testing an individual's vision are provided, the mobile device including a screen for displaying a test pattern, such as a smartphone or a tablet. 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 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.