How we see: A brief description

When light rays enter our eyes, they pass through the cornea, pupil and lens onto the retina. The retina sends light impulses to the brain via the optic nerve and the brain translates those into the images we see.


Focusing Power: The Human Lens

The cornea and the lens are responsible for the focusing power of our eyes. The lens, in particular, has three particular attributes related to focusing:

• The lens is a transparent, clear medium through which light can pass on its way to the retina
• The lens is a Focusing mechanism that helps create and project a sharp image onto the retina
• The lens is a flexible, refractive control providing clear images of objects at a wide range of near, far, and intermediate distances.

“Out of Focus” Eyes: Cataracts

As a natural part of aging, the lenses in our eyes often become clouded; clouded enough to prevent light from getting through to the retina. This condition is known as a cataract. When light rays pass through a lens that has a cataract, the light is scattered or diffused rather than being focused precisely onto the retina. This causes several vision problems including blurred vision, bright colors become dull, seeing at night is more difficult, and glasses no longer seem to help. While the most common type of cataract is related to the aging of the eye, other causes include: family history; medical problems, such as diabetes; injury to the eye; medications, especially steroids; radiation; long-term, unprotected exposure to sunlight; previous eye surgery; and other unknown factors.

A cataract is not a ‘film’ over the eye but rather a permanent clouding or yellowing of the entire lens. Cataracts cannot be prevented nor can they be ‘cured’ with diet or laser treatments. The most effective way to treat a cataract is to remove the clouded lens and replace it with an artificial lens, called an Intraocular Lens or IOL.


Treating Cataracts: IOLs / Multi-focal and Accommodative Lenses

Cataract surgery is the most commonly performed surgery in the United States with more than 2 million people having the procedure every year. During this outpatient surgery, the natural lens of the eye is removed and replaced with an intraocular lens or IOL. The good news is that today’s intraocular lens technology has revolutionized the final outcome of cataract surgery. Traditionally, the goal of cataract surgery was simply to ‘restore’ distance vision with a monofocal IOL. Today, the opportunity exists to enhance vision with an IOL that may provide a full range of vision -- near, intermediate, and far -- to minimize your dependence upon glasses.


Is cataract surgery right for you?

At OPI, both Dr. Gregory Riffle and Dr. Gregory Eippert specialize in IOLs and cataract surgery and intraocular lenses. Their extensive experience and expertise in cataract care includes complete consultations, comprehensive eye examinations, assessments and recommendations, cataract surgery and IOL implants, plus follow-up and continuing care. As with any surgical procedure there are risks and benefits, and your results cannot be guaranteed. Dr. Riffle and Dr. Eippert can help you decide whether cataract surgery is right for you, discuss the options, and guide you in the selection of an appropriate IOL for your circumstances.

Listed below is a brief overview of the IOLs offered at OPI. There are, of course, a variety of IOLs for various conditions including Toric IOLs for Astigmatism, Aspheric IOLs, and Blue Light-Filtering IOLs among others. The decision about which IOL is best for you will be made in consultation with your OPI doctor.

Traditional (Monofocal) IOL

• There are many lenses available that are designed to correct vision for distance only. This type of lens has been used for many years and could be considered the ‘gold standard’ lens for most people having cataract surgery. The option exists to use monofocal lenses with one lens set for distance in one eye and the other lens set for near in the other eye to produce an outcome called monovision thus allowing for both distance and near vision. Not all people can tolerate monovision and this should be trialed before deciding to proceed with this option.

AcrySof ReStor Multi-focal IOL

• The AcrySof ReStor IOL is made of a unique, foldable material (the first of its kind) developed exclusively for use in the eye. The design of this IOL responds to how wide or small the eye’s pupil might be allowing for both a distance and near focusing point. Additionally, the edges of this IOL are somewhat flat which is thought to improve contrast sensitivity and provide better night vision. The flexibility of this IOL provides excellent visual results allowing patients to potentially see clearly at all distances (far, intermediate, and near) and delivers a high level of glasses-free vision for cataract patients.

ReZoom Multi-focal IOL

• This multi-refractive IOL distributes light over five optical zones to enable near, intermediate, and distance vision. The second generation of the ReZoom lens was approved by the FDA in March of 2005.

Crystalens Accommodating IOL

• The first and only FDA-Approved Accommodating Lens. This IOL is designed to work with your eye in the same way as a natural lens by utilizing the ciliary muscles within the eye. The crystalens rests back in the eye to adjust for distance vision, gently flexes forward for intermediate vision, and then further forward for near vision. Movement of the crystalens is enabled by a flexible hinge on both sides of the lens. The results are effective vision at all distances – clear and focused - and patients report a reduced dependency on glasses or not needing glasses at all.

For additional information about IOLs, see the following websites:
www.allaboutvision.com
www.crystalens.com
www.acrysofrestor.com
www.rezoomiol.com