[nik282000]

Exposure time is less important than exposure type. Phones and tablets encourage mindless consumption and discourage creativity and interaction by the limiting apps and input methods.

<old man> I spent every available minute on a desktop from age 7 to 17 but that time was split between games that require 100% of your attention, and message boards where you need to backread a thread for context. </old man>

Activities that require full attention and active participation make you feel better than scrolling for an hour, whether it's an challenging game, a longform discussion, or reading a book.