User's Manual

--------------------------------------------------------------------------------------------------------------------- CDC-1 User Manual
33
◼ Contrast Test
This test is designed to measure the ability of recognizing an object in surroundings having a low illumination or
similar colors. Usual acuity test uses charts consist of black dark letters seen clearly against high illumination of white
background. However in the real world, the contrast between objects and backgrounds are close to grey, even with
good eye sight if contrast sensitivity is low there may be a problem of recognizing an object.
This test is composed of Contrast Letter Test which uses characters to check level of contrast that patients can
sense and Contrast Sensitivity Test which uses bar-shape charts made of various periods of sine pattern by
considering that according to resolution of object, the sensitivity of contrast is differ.
▪ Contrast Letter Test
Use button to change the size of charts. Use button to change its contrast by
0.1 log unit.
▪ Contrast Sensitivity Chart
It shows contrast sensitivity and cycle/degress for contrast test.
Use button to change pages and check contrast sensitivity cycle/degree of next level.
Use button can select BACK menu on the bottom of screen. At this button Press or
to back to main menu.
▪ Contrast Sensitivity Test
Begin contrast test using sine patterned charts.
Ask patient which chart on bottom is similar with the one in the middle. Use button select
the chart that patient choose. Then press to confirm.
After test is complete, contrast sensitivity and spatial frequency are shown as result.