The quick answer is yes, it is a myth that watching to much TV can harm your eyes. There are two theories as to why watching TV has a negative effect on your eyesight neither of which are true. At one point, it was felt that TVs emit radiation which damage the eye and that sitting too close to your TV would expose kids to too much of it. Regulation on TV manufacturers have insured that no TV emits enough radiation if any to cause any health problems. The second reason that has been proposed is that focusing on any one object can cause blurriness. The only truth to this claim is that focusing on near objects for a prolonged time can cause eye muscle fatigue which may result in intermittent trouble focusing towards the end of the day. No studies have shown this to have any long last effects. There are other reasons to get your kids off TV. If you can get them playing outside or reading books they may be better off. Next time you have an appointment with your kids' pediatrician
, bring up eye health and the issue of watching too much TV. He or she can give you some suggestions how to get your kids off TV. Good luck.