This paper seeks to determine the effect of lighting and light installations on open spaces and the impact of these elements on people’s mental and physical conditions. Being ubiquitous element, light is used not only for standard lighting, but also more often in the form of light installations. Even though the term 'installation' is being widely used during second half of the 20th century and later, it is still lacking exact definition, which is why the term 'light installation' also lacks exact definition. By defining the term 'installation' and studying the term 'lights', distinctions between the lighting and light installations were identified. Eventually, definition of this type of installations was proposed. In order to study the impact of light installations on the open spaces, it is necessary to determine the types of light installations. By studying and analyzing the light installations both worldwide and in Croatia, categorization of light installations was proposed. In order to obtain a better insight into people’s opinion on light installations, the survey has been conducted. Comments and needs of interviewed people were indentified, together with their preferences and opinions on the effectiveness of particular light installations. Taking into account the aforementioned elements of the paper, guidelines were established for choosing an appropriate site for specific light installation, as well as selecting the appropriate light installations for the given site.