Astigmatism and lens choice in lens surgery
Correcting astigmatism with toric lenses and comparing monofocal, extended depth of focus and trifocal lenses.
Read article ↗WHAT YOU NEED TO KNOW
- Cataract surgery can also correct refractive errors such as myopia, hyperopia and astigmatism.
- To support this planning and guidance during surgery, I use the Alcon – VERION and ZEISS CALLISTO eye systems.
- Axis guidance can be provided by marks on the surface of the eye.
Cataract surgery can also correct refractive errors such as myopia, hyperopia and astigmatism. Planning and intraocular lens selection are tailored to each eye's characteristics.
To support this planning and guidance during surgery, I use the systems Alcon – VERION and ZEISS CALLISTO eye. Digital references guide incisions and intraocular lens positioning, particularly the alignment of toric lenses to correct astigmatism.
From manual marking to digital guidance
Axis guidance can be provided by marks on the eye's surface. Digital systems superimpose references on the image the surgeon sees through the microscope.
Alcon – VERION
The Alcon – VERION system uses information collected before surgery to support planning and provide digital references in the surgical field. These references help guide incision axes and toric intraocular lens implantation.
MICROSCOPE GUIDANCE
ZEISS CALLISTO eye
CALLISTO eye projects digital references into the microscope's field of view. Using a reference image acquired with the IOLMaster, it guides toric intraocular lens alignment without manual eye marking.
As well as lens alignment, it provides guides for incision position and for the size and shape of the capsulorhexis — the opening in the front of the lens capsule. The surgeon controls the assistance functions.
Z ALIGN digital references to guide the implantation axis.
Guides for the size and shape of the capsular opening.
Demonstration images: © ZEISS. Select an image to enlarge it. Learn about CALLISTO eye ↗
These systems support implementation of the surgical plan. Lens selection, the indication and decisions during surgery still depend on the surgeon's assessment and judgement.
This information does not replace an individual medical assessment. Follow the advice of the team looking after you.
Dr. Nuno Lopes · Patient information
Editorial presentation updated on 27 October 2026. Your team's individual instructions take priority.
