Keratoconus turns the round front of your eye into a cone. A cone is the one shape a standard contact lens was never built to sit on. So a lens that worked fine last year can start to feel wrong and leave your vision smeared. But the vision keratoconus blurs is very correctable too. At almost every stage, the right contact lens can bring it back into focus. [1][2] That runs from a soft daily you already know to a large scleral lens that domes over the cone. Here is how the options line up, and how you get fitted for the right one.

What keratoconus does to your vision

Your cornea is the clear, dome-shaped window at the front of your eye. Its job is to focus light onto the retina. [1] With keratoconus, the cornea thins and bulges out like a cone. It can no longer focus light evenly. [1] Your vision turns blurry and distorted. Short-sightedness and astigmatism creep up, and a glasses prescription keeps chasing them. [1] The astigmatism here is irregular. The surface is warped unevenly, not tilted along one clean axis the way ordinary astigmatism is. That one fact drives every lens choice below.

It usually shows up young. Keratoconus often starts in the late teens or early 20s. It then shifts slowly over the next 10 to 20 years. [1] Because the cornea keeps changing, this is not one to self-diagnose or self-fit. Only an eye doctor can confirm keratoconus. Only they can decide which lens suits the stage your corneas are at.

Glasses and soft lenses: the early-stage option

In its mildest, earliest form, keratoconus acts a lot like ordinary short-sightedness with astigmatism. Glasses or soft contact lenses can correct that short-sightedness and astigmatism well. [2] This is the one stage where everyday soft toric lenses fit the picture. A toric lens is one shaped to correct astigmatism. It has to stay put on the eye to work. So the designs that resist rotation matter most here. DAILIES TOTAL1 for Astigmatism uses a PRECISION BALANCE 8|4 design to hold its place. Acuvue Oasys 1-Day for Astigmatism uses a BLINK STABILIZED design to stop the lens spinning and blurring your vision. For stronger or trickier prescriptions, extended-range monthlies like Biofinity XR and Proclear Toric XR exist for eyes that are harder to fit.

Soft lenses have a ceiling, though. As the cone steepens, a soft lens just drapes over the uneven surface and takes on its shape. At that point it stops giving sharp vision. [2] That is when most people move to a rigid design. Still in the early stage? If your eye doctor agrees, you can browse the soft toric range on the toric and astigmatism lens hub.

Rigid gas permeable lenses: the long-standing workhorse

Rigid gas permeable lenses — RGP or GP for short — are firm lenses made from an oxygen-permeable plastic. They have corrected keratoconus vision for decades. A GP lens does not follow the cornea's shape. It vaults over the cornea and makes a smooth, even surface for light to pass through. That masks the cone underneath. [2] It is why a GP lens can be sharp when a soft lens no longer is.

They are still the lens most doctors reach for. At one academic clinic, GP lenses made up about 60% of keratoconus fittings by 2020. [3] The trade-off is comfort. A firm lens takes some getting used to. The fit has to be dialled in by a specialist over several visits. Like the scleral and hybrid lenses below, a GP lens comes from that practice, not a mail-order box. Contacts Direct fills the soft-lens side of a keratoconus prescription. What you get for the effort is the sharpest vision most cones will reach.

Scleral lenses: comfort for a steeper cone

Scleral lenses answer the biggest gripe about rigid lenses. They are large gas permeable lenses. They vault over the whole cornea and rest on the sclera, the white of the eye. The space underneath fills with fluid. So the lens never touches the tender cone at all. It just builds a smooth new surface above it. Our guide to scleral contact lenses covers how they sit and who they suit.

That design has changed keratoconus care fast. The same clinic fitted no scleral lenses at all in 2010. By 2020, more than 1 in 5 keratoconus patients wore them. [3] They are often the answer for an advanced cone. They also help people whose eyes can't tolerate a smaller corneal GP lens.

Hybrid and piggyback lenses: rigid clarity, softer feel

Some wearers want the sharp vision of a rigid lens without the firm feel. Hybrid lenses are built for that. They pair a rigid gas permeable centre, which vaults over the cone for clear vision, with a soft outer skirt that makes the edge feel gentler. [4] It is a single lens doing both jobs.

Piggybacking gets to the same goal a different way. You wear 2 lenses on 1 eye. A soft lens sits against the cornea as a cushion. A GP lens rides on top for the correction. [4] A specialist reaches for either one when a bare rigid lens gives great vision but not enough comfort.

Why the fitting is the whole game

Notice what every option past the early stage shares. None of them is off-the-shelf. Keratoconus lenses have to be carefully fitted. Your eye doctor maps the cone and dials in the base curve and diameter — both measured in millimetres — often across several visits. Expect frequent check-ups and lens changes as your prescription shifts. [5][4] A rigid lens that fits one cone can be useless on another.

It helps to be clear on what these lenses do and don't do. They correct the vision keratoconus blurs. They do not cure or slow the condition itself. Your eye doctor manages that side separately, and may raise other treatments. Even after a corneal transplant, glasses or contact lenses are often still needed to see your best. [5] So the right first move at any stage is the same. See an eye-care professional, get the diagnosis and let them fit the lens to your eye.

Where Contacts Direct fits in

Once your eye doctor writes the prescription, Contacts Direct is where you fill the soft-lens side of it. That means the daily and monthly toric lenses above, in the exact powers your prescription calls for, with free shipping on every order. Specialist rigid, scleral and hybrid lenses are a different story. They are fitted and supplied through the practice that shapes them to your cornea, so they don't come from a mail-order box. Either way, your vision benefits and any FSA or HSA dollars can go toward the lenses your eyes need. Still working out where your corneas sit? Start with your eye doctor. Then use our eye-health guides and vision insurance pages to make the most of the plan you have.

Sources

[1] American Academy of Ophthalmology — the cornea is the clear, dome-shaped window that focuses light; in keratoconus it thins and bulges into a cone, causing blurry, distorted vision and growing short-sightedness and astigmatism; it often starts in the late teens to early 20s and progresses over about 10 to 20 years. aao.org

[2] National Keratoconus Foundation — glasses or soft contact lenses may correct the mild short-sightedness and astigmatism of earliest-stage keratoconus; as it progresses a rigid gas permeable lens vaults over the cornea, replacing its irregular shape with a smooth, uniform refracting surface. nkcf.org

[3] National Keratoconus Foundation / Scanzera A, Deeley M, Joslin C, et al., "Contact Lens Prescribing Trends for Keratoconus at an Academic Medical Center," Eye & Contact Lens, 2022 — GP lenses made up about 60% of keratoconus fittings by 2020, while scleral lenses rose from none in 2010 to more than 1 in 5 patients by 2020. nkcf.org

[4] All About Vision — hybrid contact lenses combine a rigid gas permeable centre that vaults over the cone with a soft peripheral skirt; piggybacking fits a GP lens over a soft lens that acts as a cushion; keratoconus wearers likely need frequent visits to fine-tune the fit and prescription. allaboutvision.com

[5] American Optometric Association — keratoconus contact lenses must be carefully fitted, with frequent check-ups and lens changes; even after a corneal transplant, eyeglasses or contact lenses are often still needed to correct vision. aoa.org