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Message: <blockquote data-quote="613Orm" data-source="post: 3217826" data-attributes="member: 107876">If the effects of my eventual eye sight problems can help someone else then I can continue with this post in which I try to provide some more information that may give some hints. I have spent all morning today doing the rotation test. I have first held the bins correctly to confirm the effect. Today I had more problems noticing it. I think it somehow depends on direction of light. Anyway, the results are as follows. I must first clarify that "right tilt" means I tilted the bins down clockwise, and "left tilt" means tilt up counter clockwise. In all positions the sweetspot was experienced as oval with horizontal length axis. Surprising maybe, but it is how I see it. Held correctly: sharpest 9 o'clock and somewhat sharper 3 o'clock. Upside down: a tiny bit (atb) sharper at 3. Left eye, left tube, correctly held: no effect (-)L eye, l tube, ups down: -L eye, l tube, right tilt: atb sharper 9L eye, l tube, left tilt: -L eye, right tube, corr: -L eye, r tube, ups down: atb sharper 9L eye, r tube, right tilt: -L eye, r tube, left tilt: -Right eye, left tube, corr: atb sharper 9R eye, l tube, ups down: -R eye, l tube, right tilt: atb sharper 9R eye, l tube, left tube: atb sharper 9Right eye, right tube, corr: -R eye, r tube, ups down: atb sharper 9R eye, r tube, right tilt: -R eye, r tube, left tilt:-I tried one of the online astigmatism tests. It was not very clear, but some lines were maybe a little blacker than the other (with best of will, if I can express it like that).I also think it is generally more difficult to see small variations with just one eye compared with two. I agree that a smaller pupil size of the binocular may influence the effect by making it more difficult to position the eyes. This is different when using the binocular with two eyes, or with just one where maybe one can vary the eye position more. It can also influence the noticed variation with light. I do not know if this brings any clarity to this, and I have not seen all that many in the posts that have experienced the same as me, so I repeat that I feel it may be something to personal to be of general interest. But, OK, leave the thread if you feel it may help others.</blockquote>

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