The article proposes a method for measuring discomfort glare which uses numerical description of the phenomenon in the form of a digital luminance distribution map recorded on a CCD array. Essential procedures for determining partial quantities which are necessary for calculation of UGR index are discussed in detail, along with techniques for measuring position index and size of light sources, with regard to the parameters of the registering system and coordinates of the images of the sources on the array.

The aim of the study was to examine how the wording of a question about audio, visual and audiovisual stimuli can affect the assessment of the environment. The participants of the psychophysical experiments were asked to rate, on a numerical scale, audio and visual information both separately and together, combined into mixes. A set of questions was used for all the investigated audio, visual, and audio-visual stimuli. The participants were asked about the comfort or the discomfort caused by the perceived stimuli presented at three different sound levels.
The results show that there are no statistically significant differences between the assessment of comfort and discomfort associated with visual samples. Actually, the comfort and discomfort ratings are equivalent to the extent that a discomfort rating can be represented as the opposite to the comfort rating, i.e. the discomfort rating is equal to the 10 minus comfort rating.
In general, the results obtained for audio and audio-visual samples were the same, with only a few exceptions that were dependent on sound level. No statistically significant differences were found for the loudest stimuli, but there were some exceptions for the softener cases. Based on the results, we show that only for visual stimuli both scales are totally interchangeable. When presenting audio and audio-visual samples, only one scale should be applied – either discomfort or comfort, depending on the context and the character of the stimuli.