OCULUS Mesotest II, Инструкция по эксплуатации

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6 Device Description
Instruction Manual Mesotest II (G/62800/0715/en) 11 / 86
6.1 Mesotest II Functionality
Description
The Mesotest II is a PD-independent, freespace instrument for testing
mesopic vision and glare sensitivity.
Freespace means that the tests are conducted under natural visual
conditions in an open space.
The device myopia is more or less eliminated, as the eyes accommodate
and converge in the same way as for natural vision.
The flexible viewer enclosure facilitates relaxed viewing and provides an
optimal fit for every patient. The enclosure completely shuts out all
extraneous light, thus allowing correct examinations to be conducted,
even in just moderately dark room conditions.
The air vents in the enclosure prevent the patient’s glasses or the unit’s
viewer glass from fogging.
Use
In Germany: The Mesotest II is used for testing mesopic vision and glare
contrast sensitivity as required by driver’s license issurance regulations
and it meets the requirements of DIN 58220, Part 7.
Testing of mesopic vision and glare contrast sensitivity is an important
supplement to photopic vision testing, especially for the assessment of
night driving ability. Pre- and post-operative testing of the mesopic vision
and glare sensitivity of patients with intraocular lenses, or those who
have undergone refractive surgery is recommended, as well as for
prescription of tinted lenses.
The device is dimensioned such that the patients’ differing inter-pupillary
distance does not affect the results.
Setup
The focussing screen of the test field is viewed through a lens via a
semi-reflector viewer mirror. The optotypes are presented in front of this
focussing screen. Their virtual image appears 5 meters away from the eye.
The optotypes are vapour-deposited on a glass substrate.
The glare light is located at the left of the test field at a visual angle of
3°. Depending on the test that has been selected, this is activated
automatically.
The glare light simulates the glare situation of an oncoming vehicle with
dimmed headlights. 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
The ambient light and the glare light are illuminated separately by one
light emitting diode each.