​Contrast sensitivity is an important measure of visual capabilities.  It complements a measure of visual acuity (which describes the finest detail visible at high contrast) by defining a subject’s ability to discern large targets at low contrast and is particularly useful in the examination of patients with reduced vision or visual impairment.

The Universal Contrast Sensitivity Test provides a straightforward, speedy method of measuring contrast sensitivity, in a convenient portable form. It has two alternative sets of targets, letters or pictures, so that it is suitable for adults, children and people of all ages with communication or cognitive difficulties.

​The size of each picture or letter remains constant throughout but the contrast of the outline of the targets reduces so that the targets become more difficult to discern against the grey background.