All of the health concerns cited are critical. But I'd like to offer yet another point of view -- one related to learning.

The research has determined that the more senses we use in the learning process, the more information we retain. This is particularly true of young children, who are active, experiential learners.

Screens employ only two senses at most: sight and sound. Consider the difference between a word comprehension activity on a screen, where a word and its definition are given, and one in which the children physically demonstrate the word. When they physically experience a word, the meaning becomes more relevant to them, and they're unlikely to forget it.

Consider the difference between a screen-based math lesson on such quantitative concepts as small/smaller, large/larger, etc., and one in which students use their bodies or manipulatives to demonstrate the concepts. Or an on-screen science lesson about habitats, versus one in which the children go outside to discover habitats or create their own in the classroom.

It's easy to be seduced by such shiny, fancy new things as digital devices. But they're not necessary to learning and are in many cases a detriment to it. Why subject our children to all the health risks of digital devices when learning without devices is superior?