NavList:

I'll wade into this one a bit:

I have been accidentally "tagged" by the sun on a few occasions whilst
taking sun shots with my 6x30 monocular. This is usually associated with
mucking about with the shades, trying to get the right combination for
viewing. Thus far, I have been lucky because my eyes have not suffered any
apparent damage. Vision is still near perfect (except for the fact that I
need reading glasses - age you know). I tend to subscribe to the "blink
response" idea as offered by Frank and others on this list.

While I would not scoff at the notion of possible eye damage caused looking
at the sun through sextant optics, I suggest that a momentary and accidental
glance is not a medical disaster and likely has no lasting effect other than
waking up the sleepy observer.

Robert
----- Original Message -----
From: <FrankReedCT@aol.com>
To: <NavList@fer3.com>
Sent: Sunday, August 06, 2006 11:57 PM
Subject: [NavList 1035] Re: Looking at the Sun through a telescope


>
> Red, you wrote:
> "Well, assuming one can trust  the BBC take a look  at
> http://news.bbc.co.uk/1/hi/sci/tech/specials/eclipse99/355066.stm
> for  actual photos of retinal damage from looking at the sun with the
> naked
> eye."
>
> First, bear in mind that that web page was created before the 1999  total
> solar eclipse, and it was partly intended to scare people (not entirely
> unreasonable in this case). You may want to read this article for a
> post-eclipse
> assessment:
> http://bmj.bmjjournals.com/cgi/content/full/319/7208/469
> I  enjoyed the little story in this article about the woman who thought
> the
> eclipse  had caused her face to turn yellow...
>
> You also wrote:
> "Now, do any of  you gentlemen honestly think using a telescope or sextant
> can
> REDUCE this  type of damage?
>
> If not, then the special case of using telescopes becomes  a moot point.
>
> I'm sure this list had this discussion a couple of years  ago. What does
> it
> really matter about the details, once one knows that  LOOKING INTO THE SUN
> MORE
> THAN FLEETINGLY CAN DAMAGE YOUR EYES?"
>
> The  damage from eclipse observing is very different from the sort of
> damage
> that one  might worry about with a small sextant telescope, and I do think
> there is more  to the issue than you're seeing right now. The damage done
> during
> eclipses  apparently arises because the eye's blink response, which
> normally
> causes us to  avert our eyes from direct sunlight, is not activated by the
> smal
> l portion of  the Sun's disk exposed when the Sun is more than about 95%
> occulted by the Moon.  You can look at the Sun with no discomfort and the
> damage is
> not apparent until  hours later.
>
> Looking at the Sun through a sextant telescope, that blink  response will
> be
> activated right away, but it may not be fast enough. It's not  the same
> issue
> as eclipse blindness.
>
> -FER
> 42.0N 87.7W, or 41.4N  72.1W.
> www.HistoricalAtlas.com/lunars
>
>
> >


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