seeing double images

[yippyfingers]

I bought an Olympus CK2 phase contrast inverted microscope from a university surplus store. One of the 10X eyepieces has a 10 X 10 grid (like an oscilloscope screen). The other eyepiece has a cross-hair reticle, like in a rifle telescopic sight. When I center the cross-hair on a slide target, I can see that the 10 X 10 grid of the other eyepiece is pretty well centered on the same target, and I am talking about looking with one eye at a time. However, when I look with both eyes, I see two images of the target and they are separated (left-to-right) by approximately 2 or 3 of the grid squares. I can also see that the cross-hair from one eyepiece is not centered (left-to-right) on the 10 X 10 grid, also a discrepancy of 2 or 3 grid squares. I say 2 or 3 because the amount of error is not consistent. I have read everything that I can find about double vision in a microscope and it seems that some people just have it because of their eyes, and not because of a scope problem. I get a headache pretty quickly when using my CK2. If this problem is with my eyes only, I will have to give up microscopy before I even get started. Does anybody have thoughts on this? Thanks.

[PeteM]

While it could be your eyesight, it's more common that the head has been knocked a bit and is slightly out of alignment. Using just your cross-hair target slide and the cross-hair reticle eyepiece, center one eyetube with one eye.

Then pull out the eyepiece, put it in the other tube, and see if it is still centered, again with the same eye. If it's off more than a bit, you might try alignment. Small adjustments can sometimes be made by loosening the screws that attach the eyetubes and nudging the tube(s) one way or the other. I like to use a specimen that has distinctive features at the edges top, bottom, left, and right. You can also try alignment to match your own eyes, should that be needed.

Do you have 20-20 eyesight? One thing that somewhat affects centration is diopter adjustments. If your eyes have wildly different eyeglass corrections and are taking your glasses off to get a good view, you might be viewing different size fields. Having one eye in good focus and the other one out, can also cause difficulties. So get both eyes in perfect focus using diopter adjustments, and then see if the fields are significantly different.

If it is a problem with your own binocular vision - fear not. You could hook up a camera and do all your viewing, focusing, composing, and picture-taking on a big monitor, laptop, tablet, or even phone screen.

[Scarodactyl]

Sometimes you get a slightly different field of view in each eyepiece l, which naturally doesn't line up. In others the fov might be the same in each and everything theoretically fine but converging them is still difficult or uncomfortable. Don't ask me why but this will likely vary from head to head even if they're nominally in spec.

[Alexander]

To have different reticles in both eye-pieces is not the best of all ideas. This is begging for problems.

[Polymerase]

Just for elimination:

Did you try adjust interpupillary distance in the viewing head? If improperly adjusted, this can cause both headaches and double vision when viewing.
In most heads, distance between the eyepieces can be adjusted. If you haven’t tried it, give it a go. Set the eyepieces to maximum distance apart, look into them and. while looking, push them together until you have one confluent round field of view.
And get new eyepieces without reticles. You don’t want the clutter while studying your specimens.

[yippyfingers]

Thanks to all of you that offered help! I have tried everything that was suggested, but no progress. I will look into using a monitor for all of my viewing. I had cataract surgery years ago and have long distance focus with both eyes, if that makes any difference. One thing I will do is to find another microscope and see if my problem travels between scopes. Again, thank you!

[yippyfingers]

I have decided to take my Olympus CK2 binocular head apart to see if I can find and fix the cause of double images. The fine folks at Evident tell me that there is a shaft inside that can possibly have a crack in it, thus causing a double image. They do not have the service manual for this part of the microscope. I wonder if anybody on this forum has one or knows where I can get one?

[yippyfingers]

I am the original poster with double images in an Olympus CK2. I had adjusted the eyepiece tubes so that the collimation was as good as I could get it. By that, I mean that I can put an eyepiece with a crosshair into the left tube and center the crosshair on a very precise target at 200X. I can then move that eyepiece to the right tube and find that the crosshair is still centered on the same target. I think this is what is meant by collimation. Yesterday, I saw my ophthalmologist for a checkup and described my problem. He said it must be my microscope being out of alignment. So, would somebody please confirm for me that a double image can result in spite of nearly perfect collimation? Also, if this is true, can it be corrected by adjusting the prisms? I know that adjusting prisms is beyond my pay grade, but that never stopped me before.

[deBult]

Ehh, maybe a trivial idea but: does another user/person have the same problem (just to eliminate your cataract surgery) ?

[Scarodactyl]

I have had stereo microscopes that seemed to be aligned on testing but nevertheless were painful for me and others to use, taking unpleasant effort to converge. Don't ask me why though. Easy enough to swap the head.

[yippyfingers]

My ophthalmologist ruled out my eyes as the source of my problem. I do not have double images except when using my Olympus CK2. I have not had anybody else trying my CK2, but that would be a really good test. Thanks. Unless somebody else chimes in, I will have to assume that collimation and alignment are two different animals. Doing some kind of an eye trick, like looking at a stereogram, I am sometimes able to make the two images converge, but I get a headache pretty quickly.