6 Device Description
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Instruction Manual Mesotest II (G/62800/0715/en)
Controls
You can operate the Mesotest II either via the control pad or via a
computer/laptop.
Control Pad:
The integrated panel illumination allows testing to be done
in a darkened room, also see
Operation via
computer/laptop
: You can also operate the Mesotest II via
a computer/laptop. You then need the Mesotest II software (available as
an optional extra), also see
Testing wit landolt rings
Testing is conducted under natural vision conditions, without device
accommodation.
Testing is done with a Landolt ring of the visual acuity level 0.1 in acc.
with DIN 58220, Part 1 (in Germany). The Landolt ring can be presented
in six different positions. Four contrast levels without glare (ambient
luminance 0.032 cd/m²) and four contrast levels with glare (ambient
luminance 0.10 cd/m²) are tested.
The optotypes can be presented in six different positions, whereby one
position is prespecified at the beginning of the test.
Four different contrast levels are available:
1:23 / 1:5 / 1:2.7 / 1:2
The contrast level 1:23 is the strongest contrast, i.e. this level is the
easiest to see.
Contrast 1:23 is the ratio of
Ambient luminance: Luminance of the optotype.
Glare light
The glare light is located on the test field.
The glare light simulates the glare situation of an oncoming vehicle with
dimmed headlights in the twilight (glare sensitivity). The glare
illuminance at pupil level is 0.35 lux.
White light emitting diodes are used as the light source. It is thus
unnecessary to change lamps.
1
Landolt ring
2
Ambient light
3
Glare light
Fig. 6-3: Glare light
1
3
2
