what is astigmatism?

Answer 1

In optics, astigmatism is when an optical system has different foci for rays that propagate in two perpendicular planes. If an optical system with astigmatism is used to form an image of a cross, the vertical and horizontal lines will be in sharp focus at two different distances

Answer 2

Astigmatism occurs when the front surface of your eye (cornea) or the lens, inside your eye, has a slightly different surface curvature in one direction from the other. Instead of being even and smooth in all directions, the surface may have some areas that are flatter or steeper. When the cornea has a distorted shape, you have corneal astigmatism. When the lens is distorted, you have lenticular astigmatism. Either type of astigmatism can cause blurred vision.

Astigmatism blurs your vision at all distances. Astigmatism is often present at birth and may occur in combination with nearsightedness or farsightedness. The condition tends to remain constant, neither improving nor deteriorating much over time.

Astigmatism is common and affects most people to some degree. Often it's not pronounced enough to require corrective action. But when it is, treatments include corrective lenses and surgery.

Answer 3

Astigmatism is when the cornea of your eye is not shaped evenly, causing you not to see as clearly as you could. Some people wear glasses to help with problem.. But now you can get contact lenses made for astigmatism. I have astigmatism in both eyes and until recently I haven't been able to wear contact lenses because they would not rest flat on my eyes which caused them to move everytime I blinked.

Answer 4

In optics, astigmatism is when an optical system has different foci for rays that propagate in two perpendicular planes. If an optical system with astigmatism is used to form an image of a cross, the vertical and horizontal lines will be in sharp focus at two different distances.

Forms of astigmatism
There are two distinct forms of astigmatism. The first is a third-order aberration, which occurs for objects (or parts of objects) away from the optical axis. This form of aberration occurs even when the optical system is perfectly symmetrical. This is often referred to as a "monochromatic aberration", because it occurs even for light of a single wavelength. This terminology may be misleading, however, as the amount of aberration can vary strongly with wavelength in an optical system.

The second form of astigmatism occurs when the optical system is not symmetric about the optical axis. This may be by design (as in the case of a cylindrical lens), or due to manufacturing error in the surfaces of the components or misalignment of the components. In this case, astigmatism is observed even for rays from on-axis object points. This form of astigmatism is extremely important in ophthalmology, since the human eye often exhibits this aberration due to imperfections in the shape of the cornea or the lens.

Answer 5

Astigmatism is an affliction of the eye, where vision is blurred by an irregularly shaped cornea. Its a problem if you want to wear contacts. Most people refer it to your cornea is shaped like a football. Here is a web page that explains it in detail.

Answer 6

it has to do with eye shape. People with astigmatism have 1 or both eyes are not round they are shaped like a football more oval. And they can be different in both eyes.

Answer 7

astigmatism is an impaired eyesight resulting usually from irregular conformation of the cornea ...a kind os defect in your optical system...i hope you know what is stigmatism ..its just the opposite of this condition

Answer 8

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Answer 9

it has something to do with your eyes my bother has astigmatism he has to wear glasses

Answer 10

in connection with your eyes it means this:
http://www.stlukeseye.com/Conditions/Astigmatism.asp