Intraocular Lens Implants

The vast majority of patients require an implant to replace the natural lens or cataract. Only in very rare cases of extreme nearsightedness is are implants unnecessary.

When the cataract, the cloudy lens, is removed, the haze is eliminated. However, the focus of the eye must be restored. Intraocular lens implants are made of a type of plastic or silicone. Since the intraocular lens is not human tissue, your body cannot reject it.

There are three materials presently used for intraocular lenses, polymethylmethacrylate (PMMA), silicone, and acrylic, with other materials under development. None of these materials is clearly superior to the others. Each has advantages and disadvantages. PMMA has been used the longest, by far, and thus has the best safety record. It must be implanted through a larger incision than the other materials. Silicone and acrylic can each be placed through a smaller incision than PMMA. Acrylics afford a very controlled unfolding of the lens, but silicone can go through a smaller incision than acrylic. Today's intraocular lenses are very safe and effective. All of the available lens materials perform admirably.

The lens implants can be folded to permit placement inside the eye through the tiny incision already made for cataract removal. The power of the lens implant is calculated to give the best distance vision possible without glasses. Bifocal lens implants may be necessary to sharpen vision for fine near tasks.

A new lens implant, the Array lens, has multiple focus points so the need for glasses is lessened.