At birth, the lens of the human eye is clear and soft, but with age, the lens becomes increasingly cloudy and hardened. As this natural process progresses, it may cause visual symptoms such as blurred vision, glare, or reduced clarity. A cataract is the medical word for the lens of the eye when it has become cloudy. Almost everyone eventually develops a cataract with age. However, the formation of a cataract can occur more quickly with sunlight exposure, certain medications, eye injury, or medical diseases such as diabetes.
Eventually, however, the cataract becomes cloudy enough to cause visual symptoms that cannot be corrected with glasses alone. At this point, cataract surgery is the only option to improve the quality of the vision. In most situations, cataract surgery is an elective surgery, and the goal of the surgery is to improve the quality of vision. There are some rare situations, however, where the cataract must be removed for the health of the eye. At the time of surgery, the natural lens is removed with a technique called phacoemulsification that utilizes ultrasound energy, and an intraocular lens (IOL) is then placed into the eye. The IOL can stay inside the eye forever.
Cataract surgery for most patients can be done with mild sedation as a same-day surgery.
Types of Intraocular Lenses:
- Basic single vision IOL: The lens can improve vision at a single distance, but most patients generally require glasses for both near and distance vision after surgery
- Astigmatism-correcting (Toric) IOL: The lens corrects astigmatism, which occurs when the front surface of the eye, called the cornea, is not roundly shaped. Astigmatism-correcting IOLs decreases the dependence on glasses for either near or distance vision, but not for both
- Tecnis Symfony Extended Depth of Focus Lens: The Tecnis Symfony Lens, FDA-approved in August 2016, is a first-of-its-kind extended depth of focus intraocular lens. It is available in both standard and astigmatism-correcting models. It can improve vision at distance, intermediate, and near range with less incidence of glare and halos.
- Presbyopia-correcting (Multifocal) IOL: The lens can improve distance vision and at the same time decrease dependence on glasses for near vision. In some patients, the lens causes glare and halos, which most often decrease with time.