A toric intraocular lens (IOL) is designed to correct corneal astigmatism as well as short- or long-sightedness during cataract or lens-replacement surgery. It has different powers in different meridians, similar to a toric spectacle or contact lens.
Function and Benefits
By neutralising pre-existing astigmatism, a toric IOL can provide clearer uncorrected distance vision than a standard spherical lens. Precise alignment of the lens within the eye is critical for optimal effect.
- Pre-operative corneal measurements determine the strength and axis required
- The lens is rotated at surgery so its markings line up with the astigmatic axis
- Small amounts of residual astigmatism may remain and can often be corrected with glasses or laser touch-up
- Toric optics can be combined with multifocal or EDOF designs in some lenses
Suitability
Toric IOLs are particularly helpful for patients with moderate or higher regular astigmatism who wish to reduce dependence on distance glasses. Irregular astigmatism or unstable corneal disease may limit benefit.
- Rotation of the lens after surgery is uncommon but may require repositioning
- Patient counselling covers expectations and the potential need for minor enhancements
- Accurate biometry and surgical technique are key to success
- Overall, toric IOLs are a well-established option for astigmatic eyes
