Screens (phones, tablets, computers, game-consoles) have many negative impacts. These impacts vary depending on the age of the user.
Damaging Effects and Some Alternatives

Here is a document that lists the damaging effects and offer some alternatives. There are Research & Resources sections with clickable links.
But Why?
Research suggests students often comprehend and retain less when reading from screens than from print. Here’s a document that explains why (and research is given on page 2).
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