San Jose Eye Institute

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What is the Crystalens?

Crystalens

The Crystalens is an intraocular lens that is implanted during cataract surgery after the cataract has been removed. In contrast to a standard monofocal lens, the Crystalens allows patients to see both far and near in focus.

Unique to this lens is that it is essentially a monofocal lens that dynamically flexes inside the eye. The Crystalens utilizes the natural muscles within the eye to adjust its shape, and thereby, its effective power within the eye. As a result, there is range of vision that is in focus, not just two separate far and near distances.

Because the Crystalens depends on the muscles of the eye to focus between far and near, its effect can be variable, depending on the strength of the eye muscles. Although some patients can see a large range of distances in focus, the majority are only able to see two of the key distances in focus, usually from far (TV, driving) to intermediate (computers, reading newspaper). Rarely, the range is less, with the Crystalens appearing to move only minimally. The effective range is not age-dependent, and cannot be predicted before surgery.

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What is a Tecnis Symfony lens?

Tecnis Symfony Lens

The Tecnis Symfony lens is an intraocular lens that is implanted during cataract surgery after the cataract has been removed. In contrast to a standard monofocal lens, the Tecnis Symfony lens has the ability to treat presbyopia, a condition that prevents patients from seeing both far and near in focus at the same time.

This lens was FDA approved in 2016 and is unique in that it is not considered a multifocal lens, such as the ReSTOR multifocal or the Tecnis multifocal. A multifocal lens gives patients two distinct distances where images are in focus, such as far and near. In between the far and near focal points, the images are not as clear. With the Tecnis Symfony lens, the images are in focus at far and near, but also everywhere in between. It provides a range of distances within which everything is in focus.

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What is a ReSTOR Multifocal?

ReSTOR Multifocal

The ReSTOR multifocal is an intraocular lens that is implanted during cataract surgery after the cataract has been removed. In contrast to a standard monofocal lens, the ReSTOR multifocal allows patients to see both far and near in focus at the same time.

This lens comes in three different options which vary in how close the near vision is away from the patient’s face. Patients can chose a lens where the near vision is at an intermediate range (useful for seeing the computer screen), one where the near vision is a little closer (useful for reading the newspaper on a table), or one that is up close (useful for near-work activities).

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What is a Tecnis Multifocal?

Tecnis Multifocal

The Tecnis multifocal is an intraocular lens that is implanted during cataract surgery after the cataract has been removed. In contrast to a standard monofocal lens, the Tecnis multifocal allows patients to see both far and near in focus at the same time.

This lens comes in three different options which vary in how close the near vision is away from the patient’s face. Patients can chose the near vision to be at an intermediate rage (useful for seeing the computer screen), a little closer (useful for reading the newspaper on a table), or up close (useful for near-work activities).

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Can I have cataract surgery after LASIK surgery?

Yes. Cataract surgery is possible after LASIK surgery. However, in cataract surgery, calculations are needed to determine the ideal power of the lens used to replace the cataract. These calculations depend on assumptions that are no longer valid after LASISK and other refractive surgeries. As a result, targeting a certain vision outcome (such as not needing glasses to see far away) is harder.

Many formulas can be used to help with the changes due to refractive surgery. Although they are helpful, they are generally not very accurate. To improve the calculations, some formulas use the clinical information from the refractive surgery. However, most of the time, this information is not even available. The latest generation of formulas take advantage of the most accurate methods of measuring the power of the cornea, the front shell of the eye.

Some instruments can only measure the front surface of the cornea. Since this is changed in refractive surgery, it is difficult to determine the cornea’s true power. More advanced instruments can now also measure the back surface. The latest formulas utilize the information from both surfaces for the most accurate calculations.

Another way to improve the outcome of the calculations is to use the ORA intraoperative aberrometer. The eye can be thought of as needing a certain refractive power to see clearly. If the eye has too much or too little refractive power, images are blurry and the eye needs some sort of refractive correction, such as glasses, to bring images back in focus.

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