A new type of permanently implanted plastic lens that may help eliminate the need for contact lenses or glasses in people with nearsightedness have recently been approved. The implanted lens also offers an alternative to laser surgery such as LASIK for people with this common vision problem.

Nearsightedness, also known as myopia, is a frequent cause of blurred vision and makes it difficult to clearly see objects in the distance.

The condition is normally inherited and is caused by a natural variation in the shape of the eyeball that makes it egg-shaped rather than round. This abnormal shape causes light to focus in front of the retina rather than directly on it.

The lens, called an intraocular lens (IOL), is similar to the type of lens that is implanted in the eye to replace the eye’s natural lens after cataract surgery. But rather than replacing the eye’s natural lens, the new lens is implanted in front of it and helps correct the eye shape imbalance and improve vision.

The lens will be sold in the U.S. It’s been approved for treating moderate to severe nearsightedness in adults age 21 and over. The IOL was introduced in Europe more than 17 years ago. Since it’s introduction, the lens has been safely implanted in more than 150,000 eyes worldwide.

The FDA based it approval on studies conducted by the manufacturer in 662 patients with moderate to severe nearsightedness in 22 medical centers in the U .S. After three years with the implant, 92% had 20/40 or better vision considered normal or near normal vision, and 44% had 20/20 or better.

FDA officials say one concern raised by the study was a loss of endothelial cells in the corneas of people who received the implants. The endothelium is a layer of cells that lines the undersurface of the cornea and needed to keep it clear.

The three year study showed a loss of these cells at a rate of 1.8% per year. It is not known whether this loss would proceed at this rate after three years or what the long term impact of this on eye health might be.

To minimize any potential risks associated with this side effect, the FDA is requiring the labeling for the new lens to specify that it should be used only on patients whose corneal endothelial cells are dense enough to withstand some loss over time.

Other side effects reported in the study include retinal detachment, cataract development, and corneal swelling. The FDA is requiring the manufacturer to conduct a five year post marketing study to assess these risks.

The lens is intended to be a permanent implant. Although it can be removed surgically, researchers say vision may not return to what it was before receiving the lens. The lens may also not completely eliminate the need for glasses because it does not correct astigmatism. Glasses may need to be worn for night driving or other activities performed in low light. They may also be needed for reading.

The distributor is currently coordinating surgeon training and certification for the new lens in the U.S. and expects to begin releasing the product to train surgeons this year.