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Science Forum Index » Medicine - Vision Forum » did they screw up my surgical loupes?...
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 Posted: Sun Jul 13, 2008 11:59 am |
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I just ordered and received a pair of surgical loupes.
It looks like this:
http://img.alibaba.com/photo/11292684/High_Resolution_TTL_Through_The_Lens_Surgical_Loupes.jpg
Aren't the telescopic lenses supposed to be centered on the pupils?
I looked in the mirror ( with loupes on ) and I'm noticing how the
lenses are a bit closer to my nose instead of being fully centered on
my pupils. Both lenses are in the medial direction rather than being
fully centered on the pupils.
Are they supposed to be like this intentionally? Will I ever become
cross-eyed from using these loupes? |
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| Posted: Sun Jul 13, 2008 4:08 pm |
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On Jul 13, 5:59 pm, infinitec... at (no spam) hotmail.com wrote:
Quote: I just ordered and received a pair of surgical loupes.
It looks like this:http://img.alibaba.com/photo/11292684/High_Resolution_TTL_Through_The...
Aren't the telescopic lenses supposed to be centered on the pupils?
I looked in the mirror ( with loupes on ) and I'm noticing how the
lenses are a bit closer to my nose instead of being fully centered on
my pupils. Both lenses are in the medial direction rather than being
fully centered on the pupils.
Are they supposed to be like this intentionally? Will I ever become
cross-eyed from using these loupes?
your lack of basic understanding of optics is telling.
you must be a surgeon (=blade). |
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| Mike Tyner... |
| Posted: Mon Jul 14, 2008 8:45 am |
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How they look is unimportant. How you see is everything.
Do you see thru them simultaneously with each eye? These scopes give a
circular field of view for each eye, like binoculars. Are the two fields
reasonably superimposed? If you have to joggle back and forth to alternate
eyes, send them back. First, re-measure the distance between your eyes.
-MT
<infinitecore at (no spam) hotmail.com> wrote in message
news:c2b5048f-e3f5-4d63-8523-2925299b6c17 at (no spam) 26g2000hsk.googlegroups.com...
Quote:
I just ordered and received a pair of surgical loupes.
It looks like this:
http://img.alibaba.com/photo/11292684/High_Resolution_TTL_Through_The_Lens_Surgical_Loupes.jpg
Aren't the telescopic lenses supposed to be centered on the pupils?
I looked in the mirror ( with loupes on ) and I'm noticing how the
lenses are a bit closer to my nose instead of being fully centered on
my pupils. Both lenses are in the medial direction rather than being
fully centered on the pupils.
Are they supposed to be like this intentionally? Will I ever become
cross-eyed from using these loupes?
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| Posted: Mon Jul 14, 2008 4:29 pm |
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Guest
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On Jul 14, 9:45 am, "Mike Tyner" <mty... at (no spam) mindspring.com> wrote:
Quote: How they look is unimportant. How you see is everything.
Do you see thru them simultaneously with each eye? These scopes give a
circular field of view for each eye, like binoculars. Are the two fields
reasonably superimposed? If you have to joggle back and forth to alternate
eyes, send them back. First, re-measure the distance between your eyes.
I don't notice any straining; the two fields together look like a
horizontal oval when I focus. There is no discomfort that I know of.
Like I said earlier, I'm questioning if the loupes were made properly.
The telescopic lenses are not centered fully on my pupils, they are
more medial towards the nose. And I actually feel that I'm moving my
eyes more medially as I'm seeing through. I can't help but feel that
I'm being cross-eyed as I'm looking through the loupes. |
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| Mike Tyner... |
| Posted: Tue Jul 15, 2008 8:08 pm |
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<infinitecore at (no spam) hotmail.com> wrote
Quote: I don't notice any straining; the two fields together look like a
horizontal oval when I focus. There is no discomfort that I know of.
That sounds like they're placed correctly. But it conflicts with your later
description of "feeling cross-eyed".
To address one of your questions - no, you can't induce esotropia in a
visually healthy adult simply by maladjusting an instrument.
Another question - the tubes _should_ be displaced a little medially because
you converge to the "near PD" when aligned for an object distance of 40-50
cm. Eyeglasses made for near are similarly displaced. Also, the two barrels
shouldn't be exactly parallel, rather pointing at the object of regard like
the legs of an isosceles triangle.
The third question - did they screw up - probably not. As long as you get
clear, simultaneous binocular vision with each eye, they have to be close.
The exit pupils of these scopes are fairly small and unforgiving, like
binoculars. Think how finicky binoculars are, when adjusting the pupil
distance - it's too easy to cut one eye off. When they're lined up properly,
the circular fields for each eye are superimposed. When they're off just a
little, you can't view simultaneously.
If they're uncomfortable and you're going to spend considerable time using
them, you can have them redone. If they don't hurt and you get good stereo
vision, the manufacturer won't see a reason to remake them.
-MT |
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