Nowadays there is a trend of using lights that use as less electrical power as possible, so called green lightening. In master´s thesis I defined different kind of lights - bulb, energy saving bulb and light emitting diode. We designed an experiment where electrical power for those kind of lights was measured by wattmeter and compared it to values that are defined on the package. Then we defined the most effective light on the bases of measured values in terms of lighting and electric power consumption that is light emitting diode. In addition we recorded the spectrum of all three kind of lights and the spectrum of sun which helped us to identify the light that suits the spectrum of sun the most. By experiment we have checked which kind of light: bulb, energy saving bulb or light emitting diode has the best impact on growth and development of garden cress, chicory and bean. After nine days of measuring we have found out that bulb has the biggest impact on growth of plants, the main reason is heat dissipation in space. We have analyzed also the impact of the same lights on growth of garden cress, chicory and bean. We found out that despite using the same kind of lights to different plants, beans have achieved the highest length. Artificial lights have also impact on what we do, not only on plants. We collected a sample of learners in seventh grade practice. We wanted to explore the impact of lights among learners in the process of reading. Through questionnaire we defined which kind of light (warm white, cool white, cool daylight) suits learners most. Half of all learners have reported that the most comfortable light is cool white. We have to warn that this is subjective opinion regarding adequacy of light. Because the theme of different kind of lights can be very useful in everyday life, we added also a preposition to conduct a technology activity day for learners in seventh grade practice. In terms of inquiry-based learning, learners can define which kind of lights are most effective and are useful in everyday life. They can also find out how different kind of lights effect on growth of plants.