Astigmatism..... Help

[Teddy]

I have astigmatism in my eyes and I am starting to think it's effecting my nites viewing.

How does the above effect me as I am not to sure. I wear glass's and It still stuggle. When I viewed through the bino's at mars, jupitor and Saturn I could not gain focus anywhere near what I thought I would see. My girl friend uses my bino's and she is always seeing so much more than me.

Will a telescope solve my problem or is there anything I can do. I cant even see plieades( spell check) with the naked eye.

Really any help proffesional or not would go down well

Thanks

Andy

Sent from my iPhone using Tapatalk

[roboticsound]

Do you have astigmatism in both eyes?

I too have an astigmatism in one eye so when using my telescope I use my good eye.

[barkis]

This is an extract fropm Wikipedia.

It may help, or ot may not, depending your particular type of astigmatism, although I'm sure you have had professional advice.

Ron.

Astigmatism is an optical defect in which vision is blurred due to the inability of the optics of the eye to focus a point object into a sharp focused image on the retina. This may be due to an irregular or toric curvature of the cornea or lens. There are two types of astigmatism: regular and irregular. Irregular astigmatism is often caused by a corneal scar or scattering in the crystalline lens and cannot be corrected by standard spectacle lenses, but can be corrected by contact lenses. Regular astigmatism arising from either the cornea or crystalline lens can be corrected by a toric lens. A toric surface resembles a section of the surface of an American football or a doughnut where there are two regular radii, one smaller than another. This optical shape gives rise to regular astigmatism in the eye.The first spectacle lenses that corrected astigmatism were made in Philadelphia in 1841.

The refractive error of the astigmatic eye stems from a difference in degree of curvature refraction of the two different meridians (i.e., the eye has different focal points in different planes.) For example, the image may be clearly focused on the retina in the horizontal (sagittal) plane, but not in the vertical (tangential) plane. Astigmatism causes difficulties in seeing fine detail, and in some cases vertical lines (e.g., walls) may appear to the patient to be tilted. The astigmatic optics of the human eye can often be corrected by spectacles, hard contact lenses or contact lenses that have a compensating optic, cylindrical lens (i.e. a lens that has different radii of curvature in different planes), or refractive surgery.

[Bizibilder]

I've just had an eye test today and asked the optician this question as I have astigmatism in my right (favourite observing) eye. He said that for stars it will not matter as they are point sources of light, however, for extended objects such as the moon (and planets) there will be a noticable effect if observing without glasses.

BUT that's not the whole story. The problem is compounded by the axis (angle) of the astigmatism (mine, of course being in the worst direction!!) for some folk the "problem" is not actually a problem at all (see an optician for a full explanation!!!!!)

[Capricorn]

Also have astigmatism and with binoculars there isn't a problem. I wear the glasses when looking through the binoculars.

If you don't wear the glass with binoculars then several questions come to mind. What is the preseciption of the glasses? If you cannot get focus without the glasses then the binoculars may not be able to compensate for the long/short sight. My binoculars cannot quite compensate for my glasses prescription.

Have the binoculars got wind up eyecups if not then they cannot be set for the wearing of glasses. Daft question but if they have wind up eye cups are they in the correct position for/without glasses.

I am guessing that the astigmatism is not the problem, it would have to be bad to have an effect. Bad as in you would not do anything without wearing glasses all the time.

If you get a scope then simply get long eye relief EP's and wear the glasses if necessary.;)

[michael.h.f.wilkinson]

I have astigmatism (cylindrical) and wearing the right glasses cancels out the problems, in particular with long-eye-relief EPs. I disagree with the optician that astigmatism does not show up in stars. Quite the contrary: it is most easily recognized in stars, because the point becomes a little bar, which may flip 90 deg as I change focus (in the cylindrical case). In extended sources, you will see lack of focus, but not as easily recognizable astigmatism.

Another issue is visual acuity, which is 1.6 in my case, meaning I have a 60% sharper view than average (when wearing glasses of course). A high visual acuity is common in near-sighted people (curiously). If your visual acuity is lower than 1.0, you will need more magnification to see the same as average observers do.

Also: do not wear bi-focals or varifocal glasses with wide-angle EPs, it ruins the effective FOV.

[themos]

Astigmatism is a problem when you are observing at low powers with a large exit pupil (binoculars usually offer this combination). The good news is that when you increase magnification, the exit pupil goes down so by the time you are hitting 1mm - 0.5mm, astigmatism does not degrade the image.

[George Jones]

I disagree with the optician that astigmatism does not show up in stars. Quite the contrary: it is most easily recognized in stars, because the point becomes a little bar

My guess at what mistake the optician made: The eye's pupil lets in a bundle of parallel rays from a star, and (when here is no astigmatism) these parallel rays are focused to a point, so a star appears as a point. Maybe the optician thinks that since a star is seen as a point, the eye only (effectively) receives a single ray from the star. With this (erroneous) "view", astigmatism wouldn't affect the point-like nature of the image.

[Teddy]

Thanks for the reply's , i find it alot to take in. I will get new up to date lenses and also see what my optition has to say and take it from there..

i just hope new lenses will help , i have both eyes effected by the way.

used a scope for the first time last night and i thought it was not to bad , just struggle with the naked eye it seems.

Thanks again

Mr Magoo !!!