Lens options for patients undergoing cataract extraction with lens implants
Monofocal implants provide a single focus when you are not wearing glasses. Depending upon the lens power selected by the eye surgeon, the eye may see best at either far, near or intermediate (midrange) distance when eyeglasses are not worn. Most people who have cataract surgery with a monofocal IOL choose to have a lens that provides good distance vision without eyeglasses. With a monofocal IOL set for distance, you will need to wear reading glasses for close-up vision. Conversely, if you choose to have a monofocal IOL set for near vision, allowing you to read without eyeglasses, then you will need eyeglasses to see clearly in the distance. With a monofocal lens and the appropriate bifocal (or trifocal) eyeglasses, you can expect to see well at all distances. Dr. Baharozian primarily implants the Acrysof® and Tecnis® monofocal lenses.
A specialty variation of the monofocal lens, called a toric lens, has recently been developed for patients with moderate to high astigmatism (a football shaped cornea). While mild astigmatism can be treated at the time of surgery by making extra tiny incisions in the peripheral cornea called limbal relaxing incisions (LRI), larger amounts of astigmatism are better treated with toric lens to provide clear vision at a single distance without glasses. Astigmatism can also be addressed with laser vision correction (PRK or LASIK). Dr. Baharozian implants the Acrysof® and Tecnis® Toric lenses as well as the Symfony® Toric lens.
Multifocal lens implants were developed to make patients less dependent on eyeglasses for both near and distance vision after cataract surgery. Multifocal lenses use specially designed focal zones on the surface of the lens. Light rays are focused through the different zones to provide sharply-focused images at both near and distance. The ability to read without eyeglasses and the reading distance can vary because of individual factors, but is generally best when the multifocal lens implant is placed in both eyes. Haloes may be present following implantation of a multifocal lens but these usually fade as the brain adapts to this new lens. Also, a laser vision correction procedure (PRK) may be needed after implantation of a multifocal lens should a significant refractive error (such as astigmatism) be present after cataract surgery. Dr. Baharozian and his medical staff will determine if each patient is a candidate for a multifocal lens. Dr. Baharozian implants the Tecnis® Multifocal and Symfony® lenses.
An additional strategy to give clear vision both at near and far without glasses is called monovision. This technique uses traditional monofocal IOLs to allow for near or intermediate vision in one eye and distance vision in the other eye. Not everyone is comfortable with this difference in focus, but many people find they adapt well to monovision when they try it out first using contact lenses before having cataract surgery.