Re: viewers for real eyes

[P3D Don Chaps <dchaps@xxxxxxx>]

On Fri, 23 Aug 1996, P3D John Bercovitz wrote:

> Don Chaps writes:
> 
> >> Better to just have your correction put in 
> >> some small lenses and put those lense near the viewer's lenses but on the 
> >> transparency side of the lenses.  
> 
> > This was a typo, right?
> 
> To the first order it doesn't matter which side of the lens you put it on.
> I have read of people successfully putting this lens on the other side of
> the ocular lens so that they won't lose any eye relief.  I have not tried 
> it myself but it sounds right to me.
> 
> John B
> 
> 
I thought about this (first post, then think - my motto). John was 
talking about adding a simple negative lens to change the focal length 
and thereby change the focussing range of the viewer. I homed in on the 
word astigmatism. Lenses correcting for astigmatism have a different 
vertical presription than horizontal prescription, not something I'd want 
in front of my ocular.
        My apologies for my confusion. All you need to do to keep me off this 
subject is take up a collection for laser surgery. ;)


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