The American Academy of Pediatrics has significantly altered their guidelines for screen time for kids. the changes are less absolute than the previous recommendation of two hours a day period. They all room for considering whether that time is spent in front of a television, tablet computer, laptop, or mobile phone, as well as age, and limits on content:
http://gizmodo.com/we-were-wrong-about-limiting-childrens-screen-time-1788065909
http://pediatrics.aappublications.org/content/early/2016/10/19/peds.2016-2591
http://pediatrics.aappublications.org/content/early/2016/10/19/peds.2016-2592
http://pediatrics.aappublications.org/content/early/2016/10/19/peds.2016-2593
https://www.healthychildren.org/English/media/Pages/default.aspx
