What is the replacement lens that is used in cataract surgery made of?

Any of several transparent synthetic materials that have been tried out over several decades of continued improvement.

The very first intraocular lens implants (IOLs) were made of a rigid plastic called PMMA (polymethyl methacrylate), the same material used in fighter plane windshields. Realizing that a smaller incision would offer faster healing, the IOL industry switched to silicone which could be inserted rolled-up and would then unfold to its normal shape inside the eye.

Gradually it became apparent that hydrophilic, and later, hydrophobic soft acrylate was better because it was physiologically more inert than silicone. Furthermore, these materials could be lathed or injection-molded into more complex optical profiles. There are other materials as well that are being used (e.g. collamer) in an ongoing effort to create an artificial lens that performs optically as well as (and maybe someday better than?) the natural human lens.

Written by J. Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic