Here we describe our product “LUVIS“ – the light box for the Pelli Robson contrast charts. Within these three steps you will create standardized test requirements with LUVIS and the Pelli Robson charts:
- stick the magnet adhesive tape on the back of the chart
- Place the chart in the LUVIS
- Start the LUVIS and check the vision contrast faultlessly
In the matter of design the inventing team has sticked to the indications of DIN EN ISO 8596 – it describes under which conditions vision and contrast test should be done.
Important: Homogeneous illumination, as required by EN ISO 8596, is not possible to be achieved with conventional room lighting.
Both fluorescent tubes illuminate the box homogeneously. Thereby the light is shed on the chart in a way that no reflection occurs. Furthermore the case offers protection against incident light. Anyone who has tried to illumiate contrast charts with conventional lighting know about these difficulties. The result depends in that case on criteria for which as a specialist you have to be responsible. With LUVIS all the risks are gone!
The meaning of the ISO 8596
According to the DIN EN ISO 8596 a background luminance (luminance between the optotypes) between 80 and 320 cd/m2 with high contrast to the optotypes is indicated for the vision test. This range is also recommended for the screening of photopic contrast sensitivity. The acceptable tolerance is indicated with ±25 %.
With LUVIS you will achieve a tolerance of ±9 % all over the whole chart! Consequently this means that a letter on the top left appears maximally 18 % lighter or darker than a letter on the bottom right.
Technical details of the LUVIS
|weight:||13,5 kg (without caster base and charts)|
|illumination:||T5 light bulbs type OSRAM HE 21 W 840, 4000°K|
|luminance:||Appr. 150 cd/m²|
|for vision charts in format:||up to appr. 85 x 69 cm|
|power supply:||230 V (use adaptor for different power!)|
|wall installation:||hanging loops on the rear of the unit|
|set up w/o base:||on a flat surface or a stand|
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order LUVIS here!
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