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Astigmatism

 


Astigmatism is a common vision problem caused by an error in the shape of the cornea. Astigmatism is a type of refractive error inside your eye, which has mismatched curves. Instead of having one curve like a round ball, the surface is egg shaped


In a perfectly shaped eye, the cornea has a round curvature. A perfect curvature bends (refract) all incoming light equally to make a sharply focused image directly on the retina, at the back of your eye. However, in an egg or irregularly shaped cornea, light rays are not bent the same, which forms two different images. These two images overlap causing the image to superpose which results in blurred vision.


Astigmatism may be present from birth, or it may develop after an eye injury, disease or surgery. Unlike Nearsightedness (myopia) or Farsightedness (hyperopia), astigmatism is not caused or made worse by reading in poor light, sitting too close to the television or squinting.






https://www.mayoclinic.org/diseases-conditions/astigmatism/symptoms-causes/syc-20353835

https://www.medicalnewstoday.com/articles/158810


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