This test at full contrast requires discrimination of the direction of long lines, which is a more demanding task than the detection acuity measured with the LEA GRATINGS® Acuity Test. The test gratings are presented to children and adults at different distances to determine at which distance the direction of lines can be perceived. Knowing the distance and which grating was used, the grating acuity values can be read from the nomograms. Includes nomograms, instructions, a storage case, and 4 disks.