ATM Re: Moon viewings & vision

[tmasnyk@surgery.bsd.uchicago.edu (Taras Masnyk)]

>It was my first really decent look
>at the full moon, and I was looking at it for some time. When I looked a
>way, I had quite large 'blob' in the vision of my right eye.
>

As the effect eventually resolved, it certainly was not permanent that time;
the effect you saw was from photobleaching- the pigment the eye uses to
detect light was bleached out by the light from the moon, and the recovery
time represents the time necessary for recovery (resynthesis) of the
pigment.  Light from the full moon, to my relatively scant knowledge,
shouldn't cause permanent damage, but I can't guarantee that damage is not
possible.  Try using a moon filter (neutral density filter) next time the
moon is near full...

All this points out that we have but two eyes- injure one by careless
observing (sun through scope, etc.) and all three-dimensional viewing is
gone, and you are left without a backup eye.  NEVER EVER look directly at
the sun with a telescope, binocular, or anything else that collects photons
(including your eyes)- one will get enough energy concentrated on the retina
to burn holes in it, with permanently lost vision (at least in that area).
As mentioned, I don't know if a full moon can give enough photons to
permanently damage vision, esp with some of the larger scopes out there
(24", 30", etc.).  Does anyone with mega-aperature fever have any experience
(hopefully not bad) with this question?

Clear, dark skies
Mud-Fud