But more importantly, what is all this screen time doing to the brain? I've been reading about kids spending hours a day on a computer at school, and I have seen some of this in action. This doesn't count after school hours that kids spend on phones or other devices at home. In light of the research and the unanswered questions, I would say that making students sit in front of a computer for hours on end is irresponsible and cruel. Parents should begin to ask districts how many hours a day their child is sitting in front of a computer. The answer might be shocking.