Astigmatism is a very common eye issue that effects most people but only a few are actually severe enough to need corrective lenses or procedures to correct the problem. Astigmatism will show itself while in the process of an eye exam. In your eye, light enters passing through the cornea. The cornea bends the light, and in unison with the prescription lens, focuses it onto the retina and the macular at the back of the eye. The retina sends the signals to the brain and forms the image of what you are actually looking at.
In an eye with no astigmatism the cornea is round and shaped like a basketball. In an eye with astigmatism the cornea is shaped oblong- more like a football. Because of the football shape the light is dispersed in many places and not directly to the retina and the macular causing blurred vision at many varying distances. It is usually caused by genetics or injury to the eye and nothing that a great pair of glasses can’t fix.