Hiding Heidi Low Contrast Face Test Sku(s): 253500 (Double Sided), 253510 (Single Sided) Description: Visual communication is the most important communication method during the first year of life. The ability to detect objects of low contrast is an important component of the visual system. For example, facial expressions are mediated by faint shadows and changes in the contours of the mouth and eyes. Determining the levels of contrast that an infant can detect helps provide baseline data for evaluating future changes. For example, deviations from usual behavior may indicate disorders that leave vision at high-contrast levels unaffected. Hiding Heidi Low Contrast Face Test are available in 2 different versions: Double Sided: Four cards printed on both sides in the following contrast levels: black, 25%, 10%, 5%, 2.5%, and 1.25%. Single Sided: Seven cards printed on one side in the following contrast levels: black, 25%, 10%, 5%, 2.5%, and 1.25%. Cards are 9" x 9" (23 cm x 23 cm). Includes instructions.