According to the new European Directive on Artificial Optical Radiation (2006/25/EC) the employer has to determine
the exposure and the assessment of risks, i.e. workers shall not be exposed above the exposure limit values, which are
based on various ICNIRP guidelines. In addition, the employer shall give particular attention, when carrying out the risk
assessment, to any indirect effects amongst others such as temporary blinding.
Since up to now no quantitative values exist in order to rank or classify artificial optical sources and its associated
capability of temporary blinding, we have investigated some aspects of glare and dazzling from a high-brightness LED
(HB-LED). With such a single device and an array consisting of 80 HB-LEDs we have found in a previous investigation
that the frequency of the blink reflex exceeds the one achieved with laser belonging to class 2 according to the
international standard IEC 60825-1, however is less than about 50 %.
The size of an after-image as a function of time and the visual acuity after an exposure from a white high-brightness LED
has been investigated in detail with 3 test persons. The results have shown that the size of an after-image on the human
retina remains nearly constant with a slight decrease over a time duration of about 12 minutes, whereas the initial visual
acuity is recovered within 30 up to 60 seconds. Linear and exponential regression descriptions are given for both