Tomey TCP-2000P, Руководство по эксплуатации

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Operation Manual
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sizes, a contrast sensitivity test measures two variables, size and contrast. The
ability to detect objects of different sizes at lower contrasts is expressed as a
contrast sensitivity function (CSF). The test determines the person’s contrast
detection threshold, the lowest contrast at which a pattern can be seen.
Only standard letter tests combined with contrast sensitivity tests can provide the
opticians with a complex knowledge about their patient’s visual condition. What is
more, Contrast Sensitivity Test can detect several diseases such as cataracts,
glaucoma, amblyopia (also known as ‘lazy eye’), AIDS, Alzheimer’s, macular
degeneration or diabetes.
5.8.3. How Contrast Sensitivity Test works?
Contrast sensitivity test (CST) shows circles (one at a time) containing sinusoidal
gratings of 5 spatial frequencies with 8 contrast sensitivity levels each.
To make
the test more reliable, the orientation of the gratings (vertical, horizontal,
inclined 15 degrees clockwise, or inclined 15 degrees counter clockwise) is
chosen at random.
The test consists of two parts:

vertical

horizontal
It is important that the practitioner marks the exact answer
of the patient,
even if it is wrong . Only then the result of
the test is reliable.
VERTICAL PART:
1. Press ‘ CONTRAST’ button to enter the test. The first circle is displayed.
The patient has to recognize the direction of the top of each grating and
name it:
left (picture 38a), vertical (picture 38b), right (picture 38c).
2. Press ‘ Right Arrow ’ if the patient’s answer is ‘ right ’.
3. Press ‘
Left Arrow
’ if the patient’s answer is ‘
left
’.
4. Press ‘ Up Arrow ’ or ‘ Down Arrow ’ if the patient’s answer is ‘ vertical ’.
5. Press ‘ NO/- ’ button if the patient’s answer is ‘ don’t know ’.
WARNING