Will Laser Eye Surgery Fix Astigmatism?

Posted August 12, 2024

TL;DR: Will laser eye surgery fix astigmatism for most people? Yes, modern laser eye surgery corrects regular astigmatism routinely and accurately, either alone or together with short or long sight.¹ Suitability depends on the regularity and strength of the astigmatism, as well as detailed corneal mapping, which this guide explains alongside how to read your prescription.

Cylinder And Axis: How to Read Your Prescription

Take out your prescription and find three numbers for each eye.

SPH, the sphere, is your basic short or long sight. CYL, the cylinder, is your astigmatism. It records its size in dioptres, although the sign convention can vary between optometrists.

AXIS, from 1 to 180 degrees, is its orientation. It describes the direction along which your cornea’s curvature differs.

“Minus 2.00 / minus 1.25 x 90” therefore means two dioptres of myopia and 1.25 dioptres of astigmatism oriented at ninety degrees. If your CYL box contains a number, you have measurable astigmatism. You are in the majority, and this page is about you.

What Astigmatism Actually Is

A cornea with no astigmatism is curved like a football, equally steep in every direction. Light therefore converges to a single point.

An astigmatic cornea is curved more like a rugby ball, with one meridian steeper than the other. Light converges at two different points and nothing lands quite crisply. Distance and near vision can both smear slightly, lights may streak at night, and the eye tires from juggling two almost-right images.

Astigmatism is extremely common, usually present from early life and usually stable. It is geometry rather than disease, which is exactly why a geometric treatment suits it.

Corneal Versus Lenticular Astigmatism

One nuance most pages skip is that not every cylinder originates solely in the cornea. The natural lens inside the eye can contribute its own astigmatism, while your spectacle prescription measures the total.

This matters because laser treats the cornea. Where the cylinder is corneal, as it usually is, laser addresses it at source. Where a meaningful share is lenticular, treatment planning accounts for it.

In an older eye whose lens is changing anyway, correcting astigmatism at the lens can become the more logical address. This can be achieved with a toric intraocular lens during lens surgery. Your assessment measures both contributions rather than assuming.

How Much Astigmatism Can Laser Treat?

Resist any page offering one blanket number because the honest answer is a planning envelope rather than a threshold.

The treatable range depends on the cylinder itself and the sphere it is combined with. It also depends on your corneal thickness, tissue budget, corneal shape and regularity, as well as the platform’s approved profiles.

Common cylinders sit comfortably within range. Large cylinders, especially those combined with large spheres, may demand more tissue than a cornea should give. The correct response to “too much for laser” appears two sections below.

The number that determines suitability is not on this page. It comes from your prescription, corneal measurements and pachymetry.

Can LASIK Treat Astigmatism? Can SMILE? Can PRK And LASEK?

Each deserves its own answer.

LASIK: yes, routinely, with the astigmatic correction folded into the excimer profile beneath the flap.

SMILE: yes, for myopic astigmatism within its approved range, with the lenticule itself sculpted asymmetrically.

PRK and LASEK: yes, with the same profiles delivered at the surface. These procedures may be considered for some patients with thinner corneas who also have astigmatism.

The technique is selected using the complete prescription, including the type and amount of astigmatism. Corneal measurements, tissue availability and the wider clinical assessment also influence the recommendation.² Each option therefore requires detailed diagnostic assessment.

What Happens to the Axis During Treatment?

An astigmatic correction only works along its intended axis, so orientation is engineered, not hoped for.

Registration aligns the treatment with your eye’s own landmarks, while the tracker follows its position continuously. Cyclotorsion compensation matters because the eye rotates slightly between sitting upright for measurement and lying flat under the laser. Without compensation, this movement could misalign the treatment axis.

This is one of the quiet places where platform quality and surgical care genuinely touch your result. A fair question to ask any provider is simply: how is my axis aligned?

What If My Astigmatism Is Irregular?

Everything above concerns regular astigmatism, which is consistent and mappable.

Irregular astigmatism is different in kind. The surface varies unpredictably from point to point, most importantly in keratoconus and related ectatic conditions. In these conditions, the cornea is biomechanically weakened and progressively distorting.

Removing tissue from such a cornea is not a correction but a rare and serious harm. This is why screening exists. Topography and tomography are designed to identify an irregular cornea before any laser treatment, although no responsible surgeon should imply that biological risk can ever be reduced to zero.³

If your scans show irregularity, the correct outcome of a laser consultation is a different conversation entirely. The focus moves to diagnosis, monitoring and non-laser options. A clinic that would proceed anyway has told you everything you need to know about it.

What If the Cylinder Is Too High for the Cornea?

Then the astigmatism is corrected somewhere else, not left uncorrected.

The toric ICL carries substantial cylinder within an implanted lens without removing corneal tissue. It has a strong published record.⁴

In an older eye where the natural lens is the real problem, toric intraocular lenses correct astigmatism during lens replacement. A meta-analysis found better uncorrected vision with toric lenses than with non-toric lenses in astigmatic eyes.⁵

A practice offering all three pathways can direct your cylinder to the structure best placed to carry it.

What If Some Astigmatism Remains After Vision Correction?

Small residual cylinder is common across all methods of vision correction and is frequently symptomless. Whether anything is done about it depends on the symptoms, not simply the number.

Options range from observation and occasional glasses for specific tasks to refractive enhancement where this is clinically appropriate and sufficient tissue remains. The applicable terms should be provided in writing before your first treatment.

Provider policies vary. Enhancement may be included for a defined period, subject to eligibility, charged separately or handled under provider-specific terms. The Blue Fin Vision® Enhancement Policy fully covers enhancement for eligible self-pay laser eye surgery patients within 24 months.

Four Example Prescriptions, Read Honestly

Minus 2.00 with minus 1.00 cylinder. Bread-and-butter territory: comfortably within range for any of the techniques on a healthy cornea, one integrated treatment, excellent prospects.¹

Minus 4.00 with minus 3.00 cylinder. A substantial combined correction: very possibly still laser, but the tissue budget, zone planning and night-vision conversation⁶ all genuinely matter. Detailed measurements guide the treatment decision.

High cylinder on a thin cornea. The budget likely says no, and the toric ICL is the honest first conversation rather than a downgrade.

Irregular topography, any numbers. Not a laser candidate; a diagnosis conversation, with the cornea’s health, not its prescription, now the subject.

So, Will Laser Eye Surgery Fix Astigmatism?

If your astigmatism is regular, within range and your cornea passes screening, the answer is yes, routinely and accurately, in the same treatment as the rest of your prescription.

If your clinical measurements indicate otherwise, the honest answer is a better pathway rather than a forced one. A detailed assessment can determine which approach is appropriate for your eyes.

References

Sandoval HP, Donnenfeld ED, Kohnen T, Lindstrom RL, Potvin R, Tremblay DM, Solomon KD. Modern laser in situ keratomileusis outcomes. J Cataract Refract Surg. 2016;42(8):1224-1234. PMID: 27531300.
Shortt AJ, Allan BD, Evans JR. Laser-assisted in-situ keratomileusis (LASIK) versus photorefractive keratectomy (PRK) for myopia. Cochrane Database Syst Rev. 2013;(1):CD005135. PMID: 23440799.
Randleman JB, Woodward M, Lynn MJ, Stulting RD. Risk assessment for ectasia after corneal refractive surgery. Ophthalmology. 2008;115(1):37-50. PMID: 17624434.
Packer M. Meta-analysis and review: effectiveness, safety, and central port design of the intraocular collamer lens. Clin Ophthalmol. 2016;10:1059-1077. PMID: 27354760.
Kessel L, Andresen J, Tendal B, Erngaard D, Flesner P, Hjortdal J. Toric intraocular lenses in the correction of astigmatism during cataract surgery: a systematic review and meta-analysis. Ophthalmology. 2016;123(2):275-286. PMID: 26601819.
Pop M, Payette Y. Risk factors for night vision complaints after LASIK for myopia. Ophthalmology. 2004;111(1):3-10. PMID: 14711706.

ABOUT THE AUTHOR

Mr Mfazo Hove
Consultant Ophthalmic Surgeon
MBChB MD FRCOphth CertLRS

Mr Mfazo Hove is a Consultant Ophthalmic Surgeon with experience spanning more than 57,000 procedures. He completed 6.5 years of specialist training at Moorfields Eye Hospital and served for five years as a consultant at the Western Eye Hospital, Imperial College Healthcare NHS Trust. He is the founder of Blue Fin Vision®, a consultant-led private ophthalmology practice operating across London, Essex, and Hertfordshire. His clinical expertise encompasses advanced cataract surgery, refractive lens replacement, laser vision correction, and implantable Collamer lenses (ICL).

A ZEISS Key Opinion Leader, Mr Hove is a respected international speaker with five invited engagements across seven cities in 2026:

ZEISS China tour (Changsha, Shanghai, and Hangzhou, April – ZEISS APAC User Meeting)
RCOphth Annual Congress – May – Manchester
ZEISS EMEA User Meeting (Istanbul)
ZEISS Lausanne User Meeting (Lausanne)
European Society of Cataract and Refractive Surgeons Annual Congress (ESCRS, London)

Book A Complimentary Consultation

Find out whether laser eye surgery could correct your astigmatism by booking a complimentary consultation with the consultant-led Blue Fin Vision® team. Bring the Laser Eye Surgery Checklist and discuss your vision correction options at one of our locations across London, Hertfordshire and Essex.

You can also review transparent treatment fees on the laser eye surgery costs page.

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