Fun fact: In an ideal world, your eye is almost perfectly round, and the lens right at the front of it, the cornea, that’s perfectly rounded, too, like the outside edge of a ball. When it’s not, when that curve is shaped more like a football than a ping-pong ball, that is a condition called Astigmatism.
In a nice, completely round eyeball with an enviably curved cornea, light first passes into your eye through the cornea. The flawlessly round cornea bends light evenly around your eye to help the eye focus.
From here, things happen pretty quickly, so try to keep up – After passing through the cornea, the light then passes through the lens of your eye, which together with the cornea focuses the light directly on the retina where special cells called photoreceptors turn light into electrical signals. These electrical signals are delivered instantaneously from the retina through the optic nerve to the brain where the brain interprets the signals as images, and thus, you see!
It turns out that in order for all that to work as it should your cornea really does need to be perfectly curved. When it’s not, that light that comes into your eye gets bent in one direction more than another meaning only one part of what you’re looking at will be in focus, sometimes something in the distance or something close-up. That is astigmatism.
It’s pretty common to have astigmatism along with nearsightedness (myopia) or farsightedness (hyperopia). All three conditions are called refractive errors because they each are involved in how your eyes bend or “refract” light.
In most cases, astigmatism is hereditary, you’re just born with it. Less commonly an astigmatism can be caused by an eye injury or surgery, and even less common than that is a rare condition called keratoconus where the cornea becomes progressively thinner and stretches to become more cone-shaped than round.
Sometimes issues with your eyes are much like the flu. It seems that every illness comes with a host of “flu-like” symptoms, so you can never be sure what you’re dealing with until you get it checked out by your doctor. Eye disorders are much the same in that they often share a lot of the same symptoms like blurred vision, eye discomfort, and headaches. If you are consistently experiencing any of those symptoms you should set an appointment for a comprehensive eye exam with your eye doctor whether you think it’s an astigmatism or not. Your doctor will be able to diagnose whatever condition it is and present you with ways to address it.
There are a few different ways to treat astigmatism, some more invasive than others. Most people choose to simply wear eyeglasses or contact lenses that are specifically designed to compensate for the refractive errors caused by astigmatism.
Alternatively, there is something called orthokeratology. Much like wearing a retainer at night to realign your teeth, orthokeratology involves fitting of a series of rigid “retainer” contact lenses worn for limited periods like overnight that work to reshape the cornea. Beyond that, there is laser or other refractive eye surgery procedures like LASIK that can be used to correct astigmatism.