What is Astigmatism?
Astigmatism is a condition where light entering the eye is not focused correctly by the cornea. As a so-called refractive error, like shortsightedness, it is not an eye disease as such. Rather, it is an optics problem.
Think of your eye like a telescope. There might be nothing ‘broken’, but if one of the parts wasn’t made right then it affects the whole thing.
Astigmatism is the name for the class of conditions where the cornea – the big lens at the front of your ‘eye telescope’ where the magnifying happens – is not the correct shape. Instead of being a perfect circle, it might be slightly oval or irregularly warped.
When this happens, it causes multiple focal positions within the eyeball. This is a problem because your eyes work best with a single focal point whose position lines up precisely with the retina on the back of your eyeball.