A recommendation from the American Academy of Pediatrics (AAP): limit your children’s screen time to two hours or less per day, none at all for under-twos. “Screen time” refers to time spent watching TV, playing on a computer. (games and educational programs), smartphone or IPad or tablet. Apart from the obvious results from lack of exercise, too much screen time is linked to emotional, social and attention span problems, poor performance at school, and a desensitization to violence.
For very young viewers, the major worries are sleep issues and a delay in language acquisition.
When I read this article I felt that it was very important to pass it on to the parents of my school.