When I was a kid, the conventional wisdom was that 6-10 feet was the requirement. Sitting any closer than 6 feet would expose yourself to harmful “stuff” eminating from a set.
Was this just an urban legend, or was there some truth to it? And what about today’s modern TV’s? If it **was ** true, does it hold true today?
Each TV has a specific distance (or range of distances) where the screen looks its’ best. This is based on the size of the screen, and the density of the pixels on the screen.
Sitting too close will cause you to notice the individual pixels, rather than having them blend into a smooth picture. It looks similar to the blocky, granulated appearance you get from expanding a digital photo too much.
But sitting too close like this doesn’t really have any harmful effects on your health, though it can cause you to get a headache.
I don’t know enough to comment about the possibility of harmful radiation from old TV sets. Somebody else will have to address that.
The very early color TV sets did emit a somewhat worrysome level of x-rays. There was some concern that sitting close for hours a day would give you a significant dose of ionizing radiation. This hasn’t really been an issue since the late 70’s – CRT design progressed to the point where x-ray emissions were made very low. Ionizing radiation emission isn’t a problem with any technology used in flat panel displays.
The optimal viewing distance for modern sets is subject to some debate. Here’s a site which gives an opinion (see the second question).