It's long, uninterrupted periods of staring at a very near object, usually lit artificially unless you have a pleasant reading space by a window. It leads almos

It's long, uninterrupted periods of staring at a very near object, usually lit artificially unless you have a pleasant reading space by a window. It leads almost invariable to nearsightedness more than just 'poor vision'. This effect is more pronounced in children due to the fact that their eyes are still growing and change shape much more easily. There have started to be myopic toddlers where this was previously a very rare genetics based phenomena.