User's Manual

--------------------------------------------------------------------------------------------------------------------- CDC-1 User Manual
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8.2.1. Vision Test
Vision test is consist of Color test and Contrast test
◼ Color Test
Color test adopted Hahn Pseudoisochromatic Plates which was introduced by Dr Hann.
Hahn Pseudoisochromatic Plates is composed of two tests, first test is Color Sensing Abnormality Detecting
Test and the second test is Color Sensing Abnormality Grading Test. The second test is conducted only when
sensing abnormality is suspected. This test is proceeded according to the patient’s answer for color charts on
the screen, when the test completes it shows the final result.
Color charts have 12 screening charts and 9 class&grade charts When it determines abnormal color vision,
it categorizes them to the first abnormal(Weak Red) and the second abnormal(Weak Green) then shows grades.
NOTE
Color Test must be executed in the condition where you can see the screen clearly. When examinee
can read a number in 3 second, and can draw a curved line in 10 second, it can be considered as
correct answers.
CDC-1 Color Vision Test would not produce the same result owing to the property of LCD panel.
Use CDC-1 test result as examinee’s guide and if necessary consult with an eye specialist.
▪ 12 Screening Charts
Below table shows how the numbers on each chart will be seen by patients having different color
sensing level.
Name
Normal
1,2 Color Defective
3 Color Defective
Color Weakness /
Blindness
Chart – 1
15
15
15
15
Chart – 2
5
3
5
X
Chart – 3
75
16
75
X
Chart – 4
8
5
8
X
Chart – 5
48
13
48
X
Chart – 6
6
X
6
X
Chart – 7
20
X
20
X
Chart – 8
7
X
7
X
Chart – 9
X
5
X
X
Chart – 10
66
66
X
X
Chart – 11
O
X
O
X
Chart – 12
O
X
O
X