The answer is true to some extent. Because the radiated electromagnetic wave, ultraviolet wave and infrared waves may be emitted out from the neon lights of TV and Computers, which do harms to peoples'eye. Especially for those who couldn't control the time of use them and do not pay attention to other important places like the habits of watching TV, the common knowledge about computer. If you have put yourself in such situation for a long time and at a close distance, you maybe let your eyes under stresses and tiredness. As time passes, your eye will feel itchy and get red. And the direct result or risk is the loss of your vision.
There is no doubt that the too much light will hurt you eyes. Eyes can not be exposed to the bright light for too much time, epically in a close distance. You would be aware of the heat from the source if it is strong enough to bother your eyes. If you look at light over 1400 nm, it will be absorbed primarily by your cornea. Also, you can sense pain in your cornea, so you will know that your eye is getting burnt. And the cornea is one of the fastest regenerating tissues.
Yes, indeed. Imagine that you stare at the sun in broad day light, well, that will just blind your eyes. I mean, strong beams, whether from the sun or other light sources, will definitely damage your eyes to some extent. So, you should control the light in the room and try to avoid strong light when you go out, sunglasses would be helpful to you. Just pay enough attention to your eyes and you may have perfect vision.