I remember as a kid, if I sat in front of the TV for too long, my mom would preach to me about how it was ruining my eyesight. I am sure that my mom isn't the only one who said that, but scientist has disputed that belief. As the scientists put it, the belief that TV can ruin your eyes in simply outdated.
When TV's first came out, they could potentially cause harm. Before the 1950's, TV emitted radiation and of course, after extended periods in front of a TV that gives of radiation, there was a chance someone could develop eye problems. Even into the 1960's, General Electric sold radiation emitting TV's that had about 100,000 times more radiation than what is considered safe. These faulty TV's were what started the myth that TV would ruin our eyes because GE sent out several warnings to not sit too close to their TV's before they fixed the radiation problem.
However, today TV's are build with a proper shield that block radiation, therefore radiation affecting our eyesight is no longer an issue. The only harm that TV could really cause if you sit in front of it for a while is eyestrain. Dr. Lee Duffner of the American Academy of Ophthalmology said that TV "won't cause any physical damage to your eyes" but again, it can cause eyestrain or fatigue. Sitting too close to the TV on the floor and looking up will strain your eyes easier studies have shown and looking at a screen with a bright light that contrasts the environment can also hurt your eyes more. However, eye strain and fatigue can be fixed very easily. People just have to turn off the TV and get some rest and their eyes will get better relatively quickly.
So ultimately, extended TV watching can only strain your eyes and will not cause any major damage. Other concerns associated with TV are more realistic like it could potentially cause other health risks such as obesity and too much TV could negatively influence kids by having them follow and imitate bad behavior they see. Also, in 2007, there was a study by the Seattle Children's Research Institute found that for every hour per day a baby watches TV, they learn 6 to 8 fewer new vocabulary words than babies who don't watch TV. So TV does have its negative effects, just not any major ones associated with your eyes that would harm your vision.
So go ahead and watch TV for a little, you won't damage your eyes.