A device to determine the contrast sensitivity of an individual's visual system by means of a series of tests in a measurement session, comprising a means for producing real time digital images, corresponding to modulated visual stimuli; and a display means for presenting said images to an individual's eye, wherein said stimuli may be modulated around an average stimulus in any direction of the color space and may be configured in their spatial and temporal characteristics for each measurement session. Said stimuli are usually chosen in the cardinal directions of the color space and respond to a sinusoidal grid pattern with spatial and temporal modulation, and with a two dimensional gaussian envelope.