Aspects of vision – Contrast


Measuring contrast sensitivity for monitoring vision changes

Contrast sensitivity testing can also effectively measure vision changes over weeks, months, or years. This could be especially beneficial in monitoring progression (or regression) of the disease process of conditions such as cataracts, age-related macular degeneration, diabetic retinopathy and glaucoma.

Contrast sensitivity testing can demonstrate whether medical treatments are effective or whether cataract surgery has resulted in improved contrast sensitivity.

The MeyeSight Test – contrast sensitivity

phoneappThe MeyeSight vision test is based on the principle that when a stimulus is presented in a scotoma (see Visual Fields link) , the time to detect and recognize that stimulus is longer than for a stimulus in a non-scotomatous area, To determine the sensitivity to contrast changes, the MeyeSight app repeats the visual acuity sequence with symbols presented at low contrast. Experience has shown that normal observers will require a symbol that is 1 or 2 steps larger. If you have reduced contrast sensitivity you will require more magnification. A difference of 4 or 5 steps is not unusual. to be written

 

Introduction    Acuity    Visual field