Contrast varies by page: full contrast, 25% , 10%, 5%, 2.5%, 1.25%, and .6%. Spiral bound. Uses different optotype combinations for each level to prevent undesired memorization. This contrast sensitivity flip book includes a series of seven contrast levels for accurate and precise vision testing. This levels decrease throughout the test beginning with acuity, 25%, 10%, 5%, 2.5%, 1.25% and ending with .6%. The use of several contrast levels help to accurately record the patients contrast sensitivity. Each test book includes instructions, recording forms and a soft tip pointer for accurate, easy and quick testing. All contrast levels are calibrated for testing and provide accurate, reliable, and repeatable results. Great for clinical studies or research.
