Special report on the aging eye

Cataract surgery involves removing a clouded natural lens from inside the eye and replacing it with a plastic one.

While the operation itself hasn't changed much over recent years, the plastic lenses have. The biggest advantage of the newer lenses is their ability to reduce the need for glasses after surgery, says a newly updated report from Harvard Medical School.

The Aging Eye: Preventing and Treating Eye Disease explains that the older types of plastic lenses help people see well at one distance - be it close up, far away, or at a medium distance. Two newer types of lenses, accommodating and multifocal, let the eye focus at varying distances, so fewer patients need glasses for reading or distance vision.

The accommodating intraocular lens has hinges on its sides that permit it to move as the eye's ciliary muscle contracts or relaxes. This improves the ability to change focus from near to far. The multifocal intraocular lens uses a new type of refractive technology to provide focus for multiple distances. This type has either small, concentric circular ridges that permit the eye to change its range of focus or broad zones to provide near, intermediate, and distance vision.

Insurers may not cover these newer lenses, and some people cannot receive them because of other medical issues. The most common problems with the newer lenses are glare, halos, and the continued need for eyeglasses.

The Aging Eye, a 48-page Special Health Report edited by Laura Fine, M.D., and Jeffrey Heier, M.D., both instructors of ophthalmology at Harvard Medical School, also covers

• glaucoma, cataract, diabetic retinopathy, and other common eye problems
• how diet affects eye health
• symptoms that should send you to the ophthalmologist
• tips for safeguarding your sight.