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The improper illumination of cultural heritage buildings and monuments can be a source of enormous light pollution, which can have a major impact on the overall environment of the illuminated area. Such lighting can be the result of carelessness or a poorly designed lighting system. This paper presents one of the methodologies that can significantly reduce light pollution, especially spilt light out of building façades. The methodology is based on using luminaires with specially made shutters and an appropriate silhouette of the object. The shutters are designed with the help of photos of the object and the location’s sizes measured. The methodology was tested during the renovation of the lighting systems of different churches in Slovenia and is described using the example of the Church of St. Thomas near Ptuj, Slovenia (N46°28.9554′, E16°0.7416′). The results show that the methodology is effective and can significantly reduce light pollution that occurs when such buildings are incorrectly lit.

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Ergonomic science at work and living places should appraise human factors concerning the photobiological effects of lighting. Thorough knowledge on this subject has been gained in the past; however, few attempts have been made to propose suitable evaluation parameters. The blue light hazard and its influence on melatonin secretion in age-dependent observers is considered in this paper and parameters for its evaluation are proposed. New parameters were applied to analyse the effects of white light-emitting diode (LED) light sources and to compare them with the currently applied light sources. The photobiological effects of light sources with the same illuminance but different spectral power distribution were determined for healthy 4-76-year-old observers. The suitability of new parameters is discussed. Correlated colour temperature, the only parameter currently used to assess photobiological effects, is evaluated and compared to new parameters.