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Instruction Manual Mesotest II
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7.4. Additional Examinations
Provided that your Mesotest II is equipped
with minus lenses and an eye cover, you
have the option of carrying out additional
examinations.
You can use the minus lenses to determine
whether night myopia is present.
Activate the minus lenses for the last test
number which the examinee just barely
recognized.
To interpose a minus lens, first press the -
DPT
.- key, then the key with the desired
lens power (marked in red on the control
unit).
If the examinee's visual performance
improves, night myopia is possibly present
and should be corrected with a
corresponding visual aid.
The degree of night myopia can be
determined by interposing different lens
powers (-0.5/-1.0/-1.5 D).
The eye cover also permits monocular
examinations to be carried out.
This is very important, e.g. for IOL patients
or excimer laser patients.
To swing the eye cover into place, press the
R/L/BIN
key on the control unit. The cover is
advanced farther each time the key is
pressed. The screen display shows which
eye is being examined ( R / L / B ).
7.5. Evaluation of Results
The test with the least contrast which is still
correctly recognized constitutes the basis for
evaluating visual performance.
For the evaluation of the
ability to drive at
night
the German Ophthalmological society
(DOG) gives following recommendations:
Driver's licence in classes: A, A1, B, BE, M, L
and T
without glare: contrast level 1 : 5 (Test 2)
with glare:
contrast level 1 : 5 (Test 6)
Driver's licence in classes: C, C1, CE, C1E,
D, D1, DE, D1E and passenger transport
without glare: contrast level 1 : 2,7 (Test 3)
with glare:
contrast level 1 : 2,7 (Test 7)
Minimum requirements concerning the
mesopic vision and glare sensitivity according
to “
Berufsgenossenschaft Principle G 25
”
(Berufsgenossenschaft: Institution for Statutory
Accident Insurance and Prevention):
Requirement level 2 (only for increased
requirement)
without glare: contrast level 1 : 5 (Test 2)
with glare:
contrast level 1 : 5 (Test 6)
Requirement level 1 (only for increased
requirement)
without glare: contrast level 1 : 2,7 (Test 3)
with glare:
contrast level 1 : 2,7 (Test 7)
As a test criterion you must operate with a
criterion to interrupt just like the DIN 58220
(visual acuity). 3 out of 5 test-signs must be
recognized correctly.
Mark an "X" in the proper space on the
"Qualified for Night Driving" line of the form
sheet. If appropriate, also give the desired
driver's licence class.
7.6. After Each Use
Turn off the unit after using it, and use the
dust cover to protect it against foreign
matter.