Two smaller groups 3.8M to 1.2M for repetitive testing (20/25, 6/7.5 to 20/8, 6/2.4 equiv.).
5 Symbols are easy to recognize.
Practical for clinical use.
Contrast sensitivity is a vital part of normal vision, especially in children. Contrast sensitivity refers to the ability to distinguish an object that may not have a defined outline. An example of low contrast sensitivity would be not being able to see the difference between a curb and the sidewalk, or not being able to see a spot on clothing.