Astigmatism is sort of a lens that has more than one focal point. A magnifying glass you take outside and try and start a campfire from the sun, focuses all the light rays to a single point. Sunlight at that point can burn.
But if you took a lens shaped like a donut edge (outer edge right at the outer edge area), and took this little lens and tried to focus the sun, you'd get a line focus where the little curve bends light, then as you moved the lens away from the paper, you'd get another line focus where the large curve focuses the light. In between would be a circular area (circle of least confusion) which would be round, but it wouldn't have that sharp focus that the regular magnifying glass has.
Most people don't really have spherical corneas, but we say that 'normal' does. The cornea sort of is spherical from the 3 to 9 axis where the lids meet. But as the lids press on the top of the cornea and the bottom of the cornea, that sort of slightly bends the cornea into a sharper bend. So the cornea may not be spherical, but have an axis that is steeper or flatter. That's the regular astigmatism thing.
So when they give us glasses, they give a number that is the sphere, then add or subtract a little power along that axis number to make the whole thing spherical. That's sort of the 'normal' astigmatism. The flat part is always 90 degrees from the more curved part. But what if it's not 90 degrees? what if it is 50 degrees?
That's irregular astigmatism. Then you can add all the scars, poorly adjusted LASEK flaps or slipped flap or scar from a trauma or injury which makes the cornea have an irregular shape...not spherical.
Now read the Optometrist's note.
2007-08-25 07:06:39
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answer #1
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answered by ? 5
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Yes. There a variety of causes of irregular astigmatism,
most commonly associated with some form of corneal scarring, (which can be quite subtle)
If not as the result of injury/infection/chemical burn, it can arise from a wide range of relatively rare heriditary conditions which normally are, I'm afraid, SLOWLY progressive.
The best known is probably keratoconus.
But there are so many possibilities it's difficult to be specific.
In the hereditary forms, it will usually affect the second eye at some point. Other causes, except atypical cataract, will tend to be static.
The optical effects of *corneal* irregularity can sometimes be reduced with soft contact lenses (especially thicker high water content ones) and often eliminated with rigid gas-permeable ones if they can be tolerated.
Sometimes laser treatment is a possiblity for static scarring or irregularity, and in some cases there is the prospect of a corneal transplant a long way down the line, *should* less drastic options prove inadequate or unsatisfactory.
One thing to emphasise is that there is almost certainly nothing you could have done, or should be doing, to make a difference to this.
The exception to that is if the corneal irregularity is due to persistent dry eye, where the various treatments for dry eye will be considered by your doctors and applied as appropriate.
Sorry I can't paint a brighter picture.
Optometrist, retired.
2007-08-25 02:20:53
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answer #2
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answered by Pedestal 42 7
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It usual means that you have bumps on the cornea. (did you have corrective laser surgery??) I have only heard about it in talking about laser surgery. Its where the laser doesnt smooth out the cornea and leaves it kind of like a dirt road. A bump here, a pothole here. I am unsure if it can get worse and I do not know if its something that will go to the other eye(but my common sense is saying no)
If you are trying to be fitted to contact lenses your best bet is to be fitted in rigid gas perm contacts. Sounds scary but its not. They are harder to get use to and have been around for years. I would talk to your doctor more about it.
Google Irregular astimatism and go from there too.
Good luck
2007-08-25 02:15:28
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answer #3
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answered by A C 3
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2016-06-20 06:45:31
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answer #4
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answered by ? 3
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Restore Your Eyesight Without Surgery - http://Eye.ClearVisionExercise.com
2016-02-05 05:11:08
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answer #5
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answered by Dolly 3
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challenging problem. query over yahoo and bing. that will will help!
2014-11-14 15:01:50
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answer #6
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answered by ? 3
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no idea. See the doctor.
2007-08-25 00:49:27
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answer #7
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answered by cly 2
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no im sorry =[
2007-08-25 00:42:44
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answer #8
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answered by Anonymous
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