The development of technology in the last few years has made life much easier, but it also brings a lot of problems. A day without screens, mobile phones, television, tablets or the Internet is almost unimaginable. Screens have become an integral part of everyday life for both, adults and children. Although, technology has many benefits, it is often overlooked how harmful excessive screen use can be. Parents play an important role in this. They decide how and in what way their children will be exposed to screens. Further, they can plan the time of exposition to screens. In that way children can havw the opportunity to continue explore the world around them. This master thesis includes an an overview of information and communication technologies that children encounter and use. Also, it analyzes the impact of screens on children of early and preschool age. The aim of the conducted research was to examine the opinions and attitudes of parents about the impact of screens on children of early and preschool age, to analyze how much time children spend using mobile devices and to determine how familiar parents are with time limits and the possible consequences of excessive use of these devices. 347 parents of early and preschool children participated in the research. At th end of the thesis, there are recommendations for the safe use of screens, in which the role of adults is highlightened.