What astigmatism is, and why cataract surgery is the moment to fix it
Astigmatism means the cornea is curved more steeply in one direction than the other, like the back of a spoon rather than a ball, so light focuses at two points instead of one and vision is blurred at every distance. Glasses correct it with a lens shaped to match. Cataract surgery replaces the eye's focusing lens anyway, so it is the natural moment to build the astigmatism correction into the eye rather than into glasses. Leaving it uncorrected is the most common reason patients still need distance glasses after cataract surgery.
Option one: a toric lens
A toric intraocular lens has the astigmatism correction built into its optic, at a power and axis chosen from your corneal measurements. It is placed like any other implant and rotated to the planned axis, guided by image registration where available and confirmed by intraoperative aberrometry where used. Toric lenses correct moderate to high astigmatism reliably and are available in monofocal, extended depth of focus and multifocal versions, so astigmatism correction can be combined with reading vision. They are the standard approach for about 1 diopter or more.
Option two: arcuate incisions
For smaller amounts of astigmatism, curved incisions placed in the periphery of the cornea at the steep axis relax that curvature and bring the two meridians closer to equal. When made with a femtosecond laser at a precise depth, length and position, they are more predictable than the manual incisions used in the past. They are often used alongside a non-toric premium lens, or to fine tune the result with a toric one.
Measuring it properly
Accurate correction depends on accurate measurement. The cornea's front and back surfaces are mapped with topography and tomography, because the back surface contributes astigmatism that older instruments missed, and modern toric calculators account for it. Dry eye distorts these measurements and is treated before they are finalized. The plan can be confirmed during surgery by image guidance and aberrometry where available.
Results
With a toric lens most patients achieve distance vision without glasses, and residual astigmatism is typically well under a diopter. Small residual amounts can be corrected later with a laser touch-up if they matter to you. Results vary from patient to patient and depend on the amount and regularity of the astigmatism, which the evaluation assesses.
Is this right for your eyes?
Nothing on this page is a diagnosis. Whether this is the right choice for you is decided by a full examination at one of our 4 offices: Pasadena, Huntington Beach, Woodland Hills and Beverly Hills.
About this content: This page was written with the assistance of AI tools and reviewed for medical accuracy by Dr. Bavand Youssefzadeh, DO. It is general information, not medical advice, and does not replace an eye examination. Individual results vary. Read our medical disclaimer.
