Why are TVs and computers bad for you eyes?

Question

Video at my eyedoctor said it's because your eyes have to refocus on all the pixels. Don't they always have to do that in real life too?

Answer 1

Stop Squinting lol

Answer 2

TVs and computers are not bad for your eyes.  The worst that prolonged usage can cause is eyestrain and headaches.  

It is true that your eyes have to constantly refocus when viewing them because the screen is constantly refreshing the image.  It is hard to explain.  Your eyes do have to constantly refocus normally but more so when using a computer or watching TV.

If you use a computer for prolonged periods of time, you should refocus your vision and look at a distant object then return to a near object and repeat the process several times about every 20-30 minutes.