My child is following in my footsteps and has been prescribed glasses for nearsightedness. Her optometrist told us she should be watching TV rather than reading books. This was both surprising and upsetting, especially since she loves reading.
This lead me on an interesting deep dive into existing research. What surprised me were the massive gaps in understanding. Scientist have at best established correlation between close up work and nearsightedness, and a negative correlation with spending time outside. The actual mechanism in play is unknown, for example the theories about sunlight are still untested. The specific types of close up work that cause issues is unknown. Some scientists have proposed that it's the contrast between white pages and black text that actually causes issues with reading.
My conclusion was that anyone who confidently asserts that $x causes nearsightedness is wrong (this thread is a case in point).
This lead me on an interesting deep dive into existing research. What surprised me were the massive gaps in understanding. Scientist have at best established correlation between close up work and nearsightedness, and a negative correlation with spending time outside. The actual mechanism in play is unknown, for example the theories about sunlight are still untested. The specific types of close up work that cause issues is unknown. Some scientists have proposed that it's the contrast between white pages and black text that actually causes issues with reading.
My conclusion was that anyone who confidently asserts that $x causes nearsightedness is wrong (this thread is a case in point).