That is a misconception and has been debunked (same goes for reading in dim light), I been a kid like that and I basically spend all day since the last 15y in front of a computer and I have near perfect eye sight. The "screen time" is not at fault per se if you get enough outside time. The reason is not just any "sunlight exposure" but it is about UV radiation that is important for the development of the eye.
The above linked study is from 14 years ago. (I linked it because it addressed arctic communities.) It's the more recent work has mostly ruled out the near-work explanation.
> ...for many years there was an assumption that long hours of study indoors, staring closely at books (near work) and never focusing on distant objects, led to myopia. This study belied that error.
> ...increased load of near work was not significantly associated with odds of myopia when factors including parental myopia, demographics, and outdoor activities were adjusted for.
wrong conclusion...it is because those people are not doing this outside ;) so yes if you sit all day at home and read books it won't be good but the reason is not the reading distance. I remember as a kid my parents always said "don't sit so close to the TV"...same story there
