According to the Cleveland Clinic, about 2 million cataract surgeries are performed annually in the United States, and in nearly all of cases, the patients receive intraocular lenses after the surgeries. Before the development of intraocular lenses, physicians prescribed eyeglasses or contact lenses after surgery. Cataract surgery removes the natural lens from the eye. Although light can still enter the eye, it will not be refracted properly, which is a function of the lens, and images will be out of focus. Intraocular lenses are lenses that are surgically inserted into eyes to replace natural lenses.
Foldable
There are two groupings of intraocular lenses. One group is foldable and the other is not. The foldable intraocular lenses have an advantage during the surgical insertion into the eye. The surgical incision can be smaller because the lens is folded during insertion. Early intraocular lenses were made with a hard plastic material that could not be folded and required larger surgical cuts, which require longer healing times.
Monofocal
Monofocal intraocular lenses are the lenses that are most commonly used, according to the American Optometric Association. A monofocal lens has the same refractive power in all areas of the lens. The lens can have a fixed focus, which provides good distance vision. Patients with fixed focus monofocal lenses may need reading glasses for seeing near objects. Other monofocal lenses can have an accommodating focus. These lenses allow for good near vision by shifting in concert with eye movements associated with changing focus.
Multifocal
Multifocal intraocular lenses act like bifocal lenses. Different areas of a multifocal lens have different refractive powers. They allow patients to see at a distance, up close and at intermediate distances. However, not all people are suited for multifocal lenses. They can cause problems with night vision and with glare. The optometrist and cataract surgeon can be consulted about the best intraocular lens for insertion after cataract surgery.
