The ability to detect objects of low contrast is an important component of the visual system. Determining the levels of contrast that an infant can detect, helps planning information for intervention and provides a baseline to evaluate future changes. Deviations from usual behavior may indicate disorders that leave vision at high contrast levels unaffected.
Visual communication is the most important way of communicating during the first year of life.
Expressions on faces are mediated by faint shadows and changes of the contours of the mouth and eyes. The cards can also be used with multihandicapped people. If an infant only responds to high contrasts, the people in his or her life should be aware of this problem and make their faces more visible. This can be done by wearing lip and eye liners, bright lipstick and eyeglasses with dark frames. Support his or her head so involuntary motor movements least affect the infant's performance.