Contrast Sensitivity

About

What is the test? The RightEye test is based on the Gratings system and requires users to judge the direction of the grated lines with varying levels of contrast.

What is the purpose of the test? This test measures the amount of lightness or darkness an object has compared with its background.

Why is this important? This test provides a full contrast sensitivity curve which is useful for the evaluation of ocular disease (cataracts, glaucoma, optic neuritis, diabetes and macular degeneration) contact lenses and refractive surgery.

The RightEye test requires test takers to judge the direction of the grated lines in cycles per degree (cpd) similar to the Michelson contrast tests. The stimuli used allows people of all ages and literacy levels to understand the goals of the test.

Life Example: An example of everyday use of contrast sensitivity is the ability to drive at night.

Metrics

Cycles Per Degree (CPD): sinusoidal gratings are frequently used to probe  the capabilities of the visual system. In these stimuli, spatial frequency is expressed as the number  of cycles per degree of visual angle.

  • 3CPD refers to the spatial frequency of the sinusoidal lines(either horizontal or vertical black lines) where three lines are present within one visual degree. 
    • A level (3CPD) tests optic nerve.
  • 6CPD refers to the spatial frequency of the sinusoidal lines where six lines are present within one visual degree.
    • B level (6CPD) tests retina.
  • 12CPD refers to the spatial frequency of the sinusoidal lines where twelve lines are present within one visual degree.
    • C level (12CPD) tests lens/crystalline or PCIOL.

Note: This test can track results over time, but we don't specify what issues come from poor contrast results. Doctors can use the poor contrast results to drive further, more specific, testing of optic neuritis or other potential clinical conditions.