"Snuffy \"Hub Cap\" McKinney" wrote:

I remember growing up it was drilled into our heads not to sit close to =
a TV screen. Then, when computers came out, it was just fine to stare =
at CRT from 2-ft away.

Early TV screens used very high powered electron guns in the CRT tube with
limited shielding around the front. Sitting close to one of those sets was a
great way to get an elevated dose of x-ray radiation.

Later sets and by the time computer mintors became common, the electron gun was
less powerful and higher amounts of leaded glass were used, resulting in reduced
exposure.