• Intraocular lenses are an important part of almost every cataract surgery. This is because the natural lens of the eye is removed during the procedure. For the eye to focus again, its lens must be replaced. Listed below are the options available for lens replacement.

  

  

• Monofocal intraocular lens implants: Traditionally, these have been used to replace the natural lens. The word "monofocal" means "one focus." You and your doctor may decide on a lens meant for close-up focusing, intermediate, or distance vision, and that is where the eye should naturally focus after the surgery. For seeing very sharply at distances other than the chosen focus, you will likely need glasses. If you are not concerned about wearing glasses to see at some or all distances, monofocal implants are the recommended choice. An option designed to give you some ability to focus at multiple distances is called monovision. With this option, one eye receives a monofocal lens designed for sharp distance vision. The other eye is implanted with a monofocal lens set to help you focus at shorter (closer) distances.
   
• Multifocal intraocular lens implants (AMO ReZoom and Alcon ReStor): In order to compensate for the eyes no longer focusing at multiple distances, as they could when you were younger, lens implant companies have created implants with not one, but two focusing points.  This effect is created by concentric rings etched on the lens (see figures below).
  
  These lens implants are best used by people who want to be as free of glasses as possible, while realizing that they may still need them for certain distances the lens focusing system does not cover. If you choose these lenses, you must also realize that they involve some visual compromise. Some patients see disturbing halos around lights, especially at night, and some experience reduced visual definition. Most people do not notice severe difficulty. If you choose these lenses, you should plan on having them implanted in both eyes, as they work best this way.

For more information on the Acrysof ReStor:  www.acrysofrestor.com
For more information on the AMO ReZoom:  www.visioninfocus.com

• Accommodating intraocular lens implants (Eyeonics Crystalens): There is a lens that is designed to increase focus without the rings described above. The advantage is that it tends to degrade the vision less than the rings. However, it does not yield as consistent focus at near (close) distances as the multifocal lens implants described above. This is because these lenses interact differently with each individual eye.

For more information on the Eyeonics Crystalens:  www.crystalens.com

• Toric intraocular lens implants: Correcting existing astigmatism (a vision problem that results in blurred images) during cataract surgery can be done with either toric intraocular lens implants or with limbal relaxing incisions, a surgical correction. There is a limit to how much astigmatism can be corrected with these techniques, but for most people, they can improve the eye’s ability to see without eyeglasses or contact lenses if this is desired.