What contact lens is best for astigmatism?
Which contact lens is best for astigmatism?
This is an interesting question from my perspective to another eye doctor's perspective. I'll explain that in a minute. But I'm writing this more for those that might need to wear a contact lens to correct their astigmatism than for those that choose a lens for astigmatism such as an eye doctor.
When I find that a person has some astigmatism I need to know how much they have. If they have about 0.75 diopters then that's about the lowest amount that a soft contact lens for astigmatism is designed to correct. Now I said soft contact lens and not a gas permeable lens. I'll also get to the gas permeable contact lens issue in a minute too.
So let's say you have 0.75 diopters of astigmatism. The doctor is generally going to try to correct that with a toric contact lens. That word toric means the surface of the contact lens is not only correcting any spherical power like nearsightedness or farsightedness, but also correcting the cylinder (astigmatism). So it really has multiple powers on the lens that will correct the multiple powers of your eye!
The question to wear a toric lens for someone has to be determined. If there is 0.75 diopters of astigmatism that might benefit the patient to wear one. The benefit should be better vision but sometimes a regular spherical contact lens will sorta help the astigmatism anyway. It's a judgment call sometimes. Usually contact lenses that correct astigmatism cost more and they might feel different. In my opinion if you haven't tried wearing a toric contact lens for your astigmatism even though you have 0.75 you might as well see if it helps. But there's no law that you have to.
If you have 1.00 diopters or more of astigmatism then I would say a toric contact lens probably would help your vision. When there is a lot of astigmatism then you certainly would see better wearing one.
Which toric soft contact lens then should you wear? The doctor is probably going to have his/her "go to" brand and since most of the newer designs work well it's not really going to matter that much brand-wise. But I have seen some lenses just not fit well on a patient's eye and so that's where the doctor evaluation is important. These soft lenses usually have some markings, very faint ones, that help determine the orientation of the lens when it's on the eye. Some calculations can be made from a lens that isn't fitting well and incorporated into what lens to try next. This is trial and error more for some patients than others. There are a lot of dynamics in getting a contact lens to fit well and stay stable so a patient can see clearly throughout the day.
Now what was I going to tell you about the doctor's perspective on a toric soft contact lens? Well, I haven't interviewed any doctor about this to be honest but I've read plenty of comments on forums that are exclusive for eye doctors. Here are a couple of important things a doctor might take into consideration of which toric lens to try.
- If there isn't much astigmatism then the doctor may not see a need if the patient sees well in their current lenses.
- If the patient complains of ghosting or second images then you might find yourself trying one.
- If the patient wants to sleep in their lenses there are some toric contact lens brands approved for that and some not approved for that.
- If the patient wants a daily disposable vs 2 week vs monthly vs quarterly. The more often you replace a lens the better it should be for your eye.
- How much astigmatism might dictate what brand you get. When there is a lot of astigmatism there are fewer choices but still plenty of good choices.
- Cost and insurance. Those should be figured out to help make the decision whether to wear toric lenses and what brand.
Now I'll briefly mention the dreaded gas permeable lens. It really isn't that bad because lately there are better ways to have these designed and fitted. There are patients wearing standard designed gas perm lenses and are happy as can be. But it's hard lens basically. It can correct the teeniest amount of astigmatism to a very high amount. And these lenses can give you very sharp vision if designed well. The number of doctors that are very active in fitting these lenses is dwindling due to the popularity of toric soft contact lenses but if your doctor recommends a gas permeable lens then you should try it. You never know!
One other issue with gas permeable lenses and astigmatism. Because the eye has basically 4 refracting surfaces (the front and back of the cornea and the front and back of the crystalline lens) the location of the astigmatism should generally be on the cornea for that lens to work the best. The doctor will be able to determine that with his/her instruments.
If you have astigmatism you have options. Do a little research but your doctor knows what to do even if you think you need to tell them what you read on the internet!