Once the cloudy human lens is removed, an intraocular lens (called an IOL) is inserted in it's place. IOL's - smaller in diameter than a dime - are made from thin flexible acrylic and are designed to last your entire lifetime without problem. IOL's have an optical power -- like glasses or contacts -- and help patients see clearly. In fact, many patients have much less reliance on glasses after surgery thanks to their IOL's.
There are two types of IOL's:
Standard IOL's - which are used for many patients across the US, permit the patient to see clearly at only one focal plane. This provides great clarity for each eye at either distance or near (but not both). Most patients receiving sandard IOL's should expect to need bifocals or reading glasses. Also, standard IOL's are not designed to correct for astigmatism - a condition that can also require glasses.
Premium IOL's - There are two classes of premium or special IOL's available to cataract patients that can offer enhanced visual outcomes. One type, called TORIC IOL's, have a special curvature built into the implant to allow us to better correct astigmatism in the eye. This can make your distance vision sharper without glasses if you have an astigmatism (25% of the population has this). Such lenses do not correct for reading -- just the astigmatism.
The other type, called MULTIFOCAL IOL's, have a trifocal type optic built into the IOL that allows patients to more easily see distance, mid range and near vision with less need for glasses. This is the most sophisticated IOL and can come with or without built in correction for astigmatism.