Joel Hunter, MD Refractive Surgeon, Hunter Vision Updated 07/02/19 5:12 PM
You may not need toric contacts for astigmatism.
Turns out that wearing a toric contact lens to correct astigmatism may actually make your vision worse. You might have a better result with regular contacts.
So What Are The Best Contacts For Astigmatism?
If your toric lenses seem to make your vision worse, switching to a regular contact lens may be the best solution.
Astigmatism is a diagnosis given to a lot of people. On the one hand, that’s fitting because the majority of people have some degree of astigmatism. On the other hand, a relatively small minority of those people have enough astigmatism to cause them to see worse than 20/20. This leads to a lot of people who are told (correctly) they have astigmatism, but then are told (usually incorrectly) they’ll have poor vision if they don’t use astigmatism-correcting contact lenses. These are called toric lenses (so named for their torus-shaped curvature). For many people—including most people with astigmatism—these specialized lenses actually lead to fluctuating and frustrating vision. People often try a few different prescriptions for toric lenses and then give up on them, with the lingering feeling that their vision isn’t being corrected as well as it should be. The feeling is reinforced when glasses, which accurately correct the astigmatism, give better vision than their contacts.
If I could accomplish one thing for you with this article, my hope is to alleviate your desire to wear toric contacts if you see well enough with your current contact lenses. There are folks with a lot of astigmatism (but it’s a minority of the population) where toric contact lenses aren’t an option—they’re a necessity. Those people, however, can answer the question of “Do I need toric lenses?” with a simple “yes” and probably aren’t reading this. (If you are in that group, however, then hello! I hope you find this interesting and can help a friend with the information someday!) But for the people who were pretty happy with their contacts until they were told to try toric contacts, maybe I can explain why they stink for you.
Does Zero Astigmatism Exist?
It’s hard to find an eye with no astigmatism. If you keep your definition of astigmatism technically correct enough, it’s impossible to find an eye with zero astigmatism. Perfect curvature doesn’t exist on anyone’s cornea, because it is teeming with epithelial cells growing, moving into place, and falling away. It is a protean, ever-shifting surface where imperfections in curvature aren’t just likely, they’re a certainty. Clearly, every person in contacts hasn’t been recommended to wear toric contact lenses, though. So where is the line drawn? Ah yes, the decision on where to cross over into toric lenses turns out to be the cause of the problem for most—and ideally the solution, if it’s redrawn correctly.
Simply Test Your Vision With Regular Contact Lenses
When you’ve got a diopter or less of astigmatism, usually you’re going to find more annoyance than help with a toric lens. How would you find this out without having your prescription in front of you? A simple, but surprisingly reliable test is whether or not you feel like your vision is pretty decent with regular contact lenses. What happens with toric lenses in these cases is you introduce a new variable into the vision. The result of a variable is, well, variable. Toric lenses add the variable of rotation. If you’ve got regular contacts, they can spin around on your eyes all day and you’re none-the-wiser. With toric contacts, if it is sitting 10 degrees off the planned axis, you’ve lost a third of its astigmatism correction and your vision looks weird.
Your toric contact lenses probably come in a box with a label that looks something like this. Here, the prescription has less than one diopter of astigmatism (highlighted in green). Also note the axis (in degrees) of astigmatism directly following it.
Part of the reason toric contact lenses have the shape they do is because a beveled, fatter lower half of the contact is designed to keep it from rotating in circles — almost like an anchor. The problem is how often it’s a super lame, ineffectual anchor. When the toric contact is rotating several degrees clockwise and counter, the fluctuating vision is noticeable and very annoying. People with low amounts of astigmatism usually fall into the group where the visual cost of those fluctuations outweigh the benefits of trying to correct the astigmatism. It’s a lot easier to see the same 20/20 all the time than to deal with a shifting, on-again-off-again 20/15.
If you were satisfied with your contacts for astigmatism and decided to try toric contacts, there’s a decent chance it wouldn’t work out very well. For this reason, it’s common to see a little bit better with your glasses (which correct the minor amount of astigmatism) than you do with your contacts. Do you need toric contacts? If you’re looking for a slight improvement from your regular contact lenses, probably not. If you needed them, it’s likely you usually stick to glasses already because contacts didn’t work for you. The other possibility is you’re the kind soul who needs toric contacts, wears them successfully, and read this blog just so you could help a friend someday.