"Fredxxx" wrote in message
...
On 08/12/2013 23:16, Gefreiter Krueger wrote:
On Sun, 08 Dec 2013 23:08:27 -0000, Fredxxx wrote:

On 08/12/2013 20:53, Gefreiter Krueger wrote:
On Sun, 08 Dec 2013 20:43:24 -0000, John Williamson
wrote:

On 07/12/2013 21:19, Gefreiter Krueger wrote:
On Sat, 07 Dec 2013 21:08:59 -0000, John Williamson
wrote:

On 07/12/2013 17:06, Gefreiter Krueger wrote:


It takes between one and ten seconds of exposure to arc light
depending
on how far away from the arc you are and how powerful it is. One
second
for a small arc weld at arm's length, ten for the same arc at the
other
end of a large workshop. Less than a second if you're holding the
business end of the welder in your hand at the end of a bent arm and
are
looking closely at the workpiece when the arc strikes. You won't
feel it
for up to five minutes, by which time it's too late.

I've definitely exceeded 10 seconds watching someone else at about 2
metres on a few occasions, with no effect.

They're your eyes, do as you wish. Just don't expect us to be grateful
for picking up the tab for your stupidity via the NHS.

I was just pointing out they aren't as sensitive as made out in here.
Perhaps like with sunburn we all have differnt levels of tolerance.

The skin is designed to cope with extended periods of sunlight. You
seem to forget that our outer skin is effectively composed from dead
cells. I would hope the retina has few dead cells. Looking at light
containing UV will help kill a few more.

We've been looking at the sun for millions of years.

Why do you think your eyes are less sensitive to damage than others?

Because of people saying they got sore eyes after a small exposure, and
I haven't.

There are two mechanisms here. First is UV damage to the cornea or
conjunctiva, the other is damage to the retina.

The first causes irritation which can be temprary, though may well
accelerate the formation of cataracts. The latter is more sinister and
not obvious. If you find looking at a bright light painless then your
sight is more susceptible to damage than normal folk.

How old are you, as you're acting like a spotty teenager?

I'd guess he's prolly pregnant, due to give birth to a parrot or two.



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