Scleral Lenses for High Astigmatism

Most astigmatism is corrected comfortably with glasses or standard toric soft lenses. But for some patients with high levels of astigmatism — even without any underlying corneal disease — standard lenses don’t rotate predictably enough on the eye to give consistently sharp vision, or simply aren’t available in a strong enough prescription. Scleral lenses are one option worth considering in these cases.

Understanding astigmatism

Astigmatism occurs when the cornea, or occasionally the lens inside the eye, isn’t perfectly spherical, causing light to focus at more than one point rather than a single sharp point. Mild to moderate astigmatism is extremely common and easily corrected with a standard toric lens or glasses prescription. High astigmatism, while less common, presents specific fitting challenges because the visual impact of any lens rotation or movement is magnified.

Why high astigmatism can be difficult to correct

Standard toric soft lenses rely on staying in a stable rotational position on the eye to keep the correcting power aligned correctly. With higher levels of astigmatism, small amounts of lens rotation or movement have a bigger effect on vision quality, which can mean fluctuating or inconsistent clarity through the day.

How scleral lenses help

Because a scleral lens rests on the sclera and is much less prone to movement or rotation than a soft lens, it can hold a toric correction more stably in place. Scleral lenses with a toric periphery are specifically designed for eyes where the sclera itself is asymmetric, which is common alongside high astigmatism.

Toric scleral lens design in more detail

A toric periphery means the landing zone of the lens — the part resting on the sclera — is designed with different curvatures in different meridians, matching the sclera’s own asymmetric shape rather than assuming it’s perfectly round. This is a separate consideration from the optical correction for astigmatism itself, and some patients need both: a toric periphery for scleral shape, and a toric optical correction for the astigmatism being corrected. Topography and scleral shape assessment help determine whether this level of customisation is needed for your specific eyes.

Who this typically suits

These are usually patients for whom simpler options have already been tried:

• High astigmatism in an otherwise healthy, regular cornea
• Astigmatism combined with other corneal irregularity, such as keratoconus or PMD
• Patients who’ve found standard toric soft lenses give inconsistent or rotating vision
• Patients whose astigmatism prescription exceeds what’s available in standard soft toric lens ranges

What to expect from fitting

Fitting for high astigmatism without other corneal disease follows a similar process to other scleral lens fittings — topography and scleral shape assessment, diagnostic lenses to confirm rotational stability and optical alignment, and anterior OCT imaging to check the final fit. Because the underlying cornea is often regular rather than diseased, some patients find this a more straightforward fitting process than those needed for significant corneal irregularity.

Astigmatism combined with other conditions

It’s worth noting that high astigmatism frequently occurs alongside other corneal conditions covered elsewhere in this cluster, particularly keratoconus and PMD, where irregular astigmatism is part of the underlying disease process rather than a standalone refractive finding. If your astigmatism is linked to one of these conditions, fitting considerations are guided primarily by the underlying condition, with the astigmatism correction built into that broader design.

Why some patients switch from glasses rather than soft lenses

Not every patient considering scleral lenses for high astigmatism has necessarily tried soft toric lenses first — some come directly from glasses, particularly if they’ve been told in the past that their prescription is too high for standard soft lens ranges, or if they simply prefer not to deal with the rotational stability issues soft toric lenses can have at high powers. Either starting point is reasonable to discuss at assessment.

Vision quality throughout the day

One of the more commonly reported benefits among high astigmatism patients who switch to scleral lenses is more consistent vision throughout the day, rather than the subtle fluctuations that can occur with a soft toric lens as it settles or rotates slightly with blinking and eye movement. For patients doing precision visual work, or simply those who’ve found this fluctuation frustrating, this consistency is often cited as the main reason for choosing scleral lenses over continuing with soft toric lenses.

Cost and commitment considerations

As with any scleral lens fitting, cost and the fitting process itself are worth weighing against your specific situation — high astigmatism without other corneal disease is sometimes manageable with simpler, lower-cost options, and it’s worth an honest conversation about whether scleral lenses represent the right level of investment for your particular case, rather than assuming the most advanced option is automatically necessary.

Making the decision with confidence

If you’re weighing up whether high astigmatism warrants scleral lens fitting, the most useful step is a proper assessment rather than trying to decide in the abstract. Topography and a discussion of your specific experience with any lenses you’ve already tried will give you and us a much clearer basis for the decision than general information alone can provide.

Bringing your lens history to your assessment

If you’ve previously worn soft toric lenses, corneal RGP lenses, or simply glasses, bringing details of your experience — what worked, what didn’t, and why you stopped if you did — gives us valuable context for planning your scleral lens assessment. This history often points toward specific fitting considerations before topography has even been performed.

Ultimately, high astigmatism is one of the more straightforward reasons for scleral lens fitting when there’s no accompanying corneal disease, and many patients in this category find the process quicker and more predictable than fittings for significant corneal irregularity.

Life with a stable toric scleral lens

Patients who move to scleral lenses specifically for high astigmatism often describe a noticeable change in day-to-day visual experience — less awareness of vision subtly shifting in and out of focus through the day, and more confidence in tasks requiring sustained visual precision, from detailed work to driving in varied lighting conditions. This consistency, more than any single measurement, is often what patients value most about the switch.

If you recognise this pattern in your own experience with glasses or soft lenses, it’s worth having a conversation with us about whether scleral lenses might offer the stability you’ve been missing.

Considering the full picture before deciding

As with every condition covered in this cluster, the decision to pursue scleral lenses for high astigmatism works best when it’s grounded in an actual assessment of your eyes rather than general reading alone. Topography, a discussion of what you’ve already tried, and a clear conversation about your specific goals together give a much more reliable basis for choosing the right path than trying to match your situation to a generic description.

High Astigmatism FAQs

Can scleral lenses correct very high astigmatism better than soft lenses?

For high levels of astigmatism, scleral lenses can offer more consistent vision than soft toric lenses because they’re much less prone to rotating or moving on the eye during wear.

Do I need a scleral lens if I just have astigmatism and no other eye condition?

Not necessarily — many patients with astigmatism, even fairly high levels, do well with standard toric lenses. Scleral lenses tend to be considered when standard options haven’t given stable, comfortable vision.

Are scleral lenses for astigmatism more expensive than standard toric lenses?

Yes, generally, because of the custom design and fitting process involved — see our guide to scleral lens costs for more detail on what affects the price.

What is a toric periphery, and do I need one?

A toric periphery is a scleral lens design feature that accounts for asymmetry in the sclera itself, separate from the optical correction for astigmatism. Whether you need one depends on your individual scleral shape, assessed at fitting.

Book a Scleral Lens Assessment

Call the practice on 0141 943 3300 to arrange a scleral lens consultation.