2024-06-01
If you have been told you have astigmatism and cannot wear contact lenses, you received outdated information. That might have been true 30 years ago, but modern toric contact lenses can correct most astigmatism just as effectively as glasses. The fitting process is a bit more involved, and the lenses cost a bit more, but the results are excellent for the majority of people.
Let us start by clearing up what astigmatism actually is, because there is a surprising amount of confusion about it.
What Astigmatism Actually Is (It Is Not a Disease)
Astigmatism simply means your cornea or lens is not perfectly round. Instead of being shaped like a basketball (spherical), it is shaped more like a football or the back of a spoon (more curved in one direction than the other). This causes light to focus at two different points instead of one, which makes things look blurry or stretched at all distances.
Astigmatism is incredibly common. About one in three people has some degree of it. It is not a disease, it is not caused by reading in dim light or sitting too close to the TV, and it does not get worse from doing anything in particular. It is just the shape your cornea happens to be. Most people are born with it, and it tends to stay relatively stable throughout life.
You can have astigmatism by itself, or in combination with nearsightedness (myopia) or farsightedness (hyperopia). On your prescription, astigmatism shows up as the "cylinder" and "axis" numbers. The cylinder is the amount, and the axis is the angle or direction.
How Toric Lenses Work
A standard spherical contact lens has the same power across its entire surface. It does not matter how it sits on your eye or if it rotates, because the correction is the same in every direction.
A toric lens has different powers in different meridians, specifically designed to match the different curvatures of your astigmatic eye. Because of this, the lens must stay in a specific orientation on your eye. If it rotates, the astigmatism correction is misaligned, and your vision blurs.
To keep the lens stable, manufacturers use several clever designs:
- Prism ballast: The lens is slightly thicker at the bottom, so gravity pulls it into the correct position. This is the most common stabilization method.
- Thin zones: The top and bottom of the lens are thinned, and the eyelids squeeze the lens into alignment with each blink. Also called "accelerated stabilization design."
- Truncation: The bottom edge of the lens is flattened slightly, and the lower eyelid keeps it oriented. Less common in modern soft lenses.
When a toric lens fits well, it stabilizes within a few blinks after insertion and stays put throughout the day. When it does not fit well, it rotates intermittently and causes frustrating moments of blurry vision. This is why the fitting process matters so much.
Why Fitting Takes Longer (and Why That Is Normal)
A standard spherical contact lens fitting is relatively straightforward. With a toric lens, your optometrist needs to:
- Measure the amount and axis of your astigmatism precisely
- Select a trial lens and evaluate how it sits and rotates on your eye
- If the lens settles at an angle that is off from the ideal, compensate by adjusting the prescribed axis
- Possibly try a second brand or base curve if the first lens does not stabilize well
This means your first appointment might involve trying one or two different lenses and then coming back a week later after wearing them in real conditions. It is not unusual to need two or three visits to dial in the perfect toric fit. This is normal, not a sign that something is wrong.
Some practitioners skip the follow-up and just hand you a prescription. If your toric lenses are uncomfortable or your vision fluctuates when you blink, go back. A lens that rotates 10 degrees off-axis can blur your vision noticeably, and the fix is often as simple as trying a different brand with a different stabilization design.
Cost: How Much More Are Toric Lenses?
Toric lenses typically cost 20 to 40% more than equivalent spherical lenses. The manufacturing process is more complex (each lens has a specific orientation that must be marked and verified), and the fitting requires more chair time.
As a rough guide for daily disposable lenses:
| Lens Type | Approximate Cost per Eye per Month |
|---|---|
| Standard spherical daily | $25 - $35 |
| Toric daily | $35 - $50 |
Monthly toric lenses are cheaper per year than daily toric lenses, but you have the added cost of solution. For many patients, the convenience and comfort of daily disposables justifies the premium, especially since toric lenses are slightly thicker and can accumulate deposits faster on a monthly schedule.
When Regular Contacts Might Be Good Enough
Not all astigmatism requires a toric lens. If your cylinder is -0.75 or less, a well-fitted spherical lens may give you perfectly acceptable vision. The soft lens material can partially mask very low amounts of astigmatism by conforming to the cornea's shape. Your optometrist can trial a spherical lens first and see if you are happy with the clarity before stepping up to a toric.
Many patients with -0.75 cylinder wear spherical lenses without any issue. Over -1.00, most people notice the difference and benefit from a toric correction.
When to Consider Rigid Gas Permeable (RGP) Lenses
For high or irregular astigmatism (typically over -2.50 or in cases of keratoconus), soft toric lenses may not provide crisp enough vision. This is where rigid gas permeable lenses shine. Because they are made of a firm material, they create their own smooth optical surface over the irregular cornea, essentially replacing the cornea's shape with a perfect one.
RGP lenses provide sharper vision than soft torics for high astigmatism, but they take longer to adapt to (typically 1 to 2 weeks of gradually increasing wear time), and they are more prone to dislodging during sports or windy conditions. Modern designs are much more comfortable than the old hard lenses, but they are still a different experience from soft lenses.
A hybrid option exists: lenses with a rigid centre for sharp optics and a soft skirt for comfort. Brands like SynergEyes offer these, and they can be a great middle ground for patients who need RGP-level optics but prefer soft-lens comfort.
Tips for Toric Lens Wearers
- Insert the lens and blink a few times before judging your vision. Torics need a moment to settle into position.
- If your vision is intermittently blurry, the lens is rotating. Do not push through it. Go back to your optometrist for a refit.
- Do not substitute brands without checking with your prescriber. Different toric brands have different stabilization designs, and a switch can mean the difference between stable and rotating.
- Keep your glasses prescription current as a backup. Toric lenses are slightly less forgiving of skipped follow-ups than spherical lenses.
The Bottom Line
Astigmatism is ordinary, not exotic. Toric contact lenses handle it well for the vast majority of prescriptions. The fitting process takes a bit more time and the lenses cost a bit more, but the end result is clear, comfortable vision in contacts. If you have been avoiding contacts because someone told you astigmatism makes them impossible, it is time for a second opinion.