In adults, visual acuity is measured as "recognition acuity," using standard line tests. However, this type of test cannot be used in examining normal infants or infants and children with multiple handicaps. Visual acuity in these individuals is measured with grating acuity tests (preferential looking). The handle allows the tester to hold the test easily. Includes instructions and storage case. Four paddles, printed on both sides. Grating levels printed on each handle are: 0.25, 0.5, 1.0, 2.0, 4.0, and 8.0 cpcm (cycles per centimeter of surface).
A preferential looking tool where the infant or child detects the presence of parallel lines of decreasing width, a task simpler than recognizing optotypes. When a striped pattern is presented in front of an infant simultaneously with a gray surface of the same size and luminance, the infant is likely to look at the striped pattern because there is more to see than on a gray surface.