Intraocular Lenses (IOLs):
Artificial intraocular lenses, or IOLs, replace the eye's natural lens that is removed during cataract surgery. IOLs have been around since the mid-1960s, though the first FDA approval for one occurred in 1981. Before that, if you had cataracts removed, you had to wear very thick eyeglasses or special contact lenses in order to see afterward, since the natural lens that had been removed wasn't replaced with an artificial one.
Aspheric IOLs
Traditional IOLs are spherical, meaning the front surface is uniformly curved. Aspheric IOLs, first launched by Bausch & Lomb in 2004, are slightly flatter in the periphery and are designed to provide better contrast sensitivity.
Premium IOLs: Multifocal & Accommodating
Traditional IOLs are monofocal, meaning they offer vision at one distance only (e.g., far, intermediate or near). They definitely are an improvement over the cataractous lens that is replaced during surgery, which provides only cloudy, blurred vision at any distance. But traditional IOLs mean that you must wear eyeglasses or contact lenses in order to read, use a computer or view objects at arm's length.
The new multifocal IOLs offer the possibility of seeing well at more than one distance, without glasses or contacts. Examples of multifocal IOLs are different versions of Alcon's AcrySof IQ ReSTOR.
Toric IOLs for Astigmatism
Toric IOLs designed to correct astigmatism (a common optical defect resulting from oval rather than spherical shape of the cornea) also are considered "premium" lenses, and — like multifocal and accommodating IOLs — likely will cost you extra because of benefits that are unavailable in conventional IOLs.
Monovision With Intraocular Lenses
If your cataract surgery involves both eyes, you might consider monovision. This involves implanting an IOL in one eye that provides near vision and an IOL in the other eye that provides distance vision.
People who do best with this method already are accustomed to monovision with contact lenses, which is a common way of correcting presbyopia (age-related difficulty seeing at near). If you cannot adjust to monovision after your cataract surgery, you may wish you had tried a multifocal or accommodating IOL instead.