Intraocular lenses (IOL's) are lenses, made from either plastic or silicone. which are used to replace the lens which will be removed during cataract surgery.

IOL's can be used to correct farsightedness, nearsightedness, and presbyopia.

The lenses, which are less than 1/4 inch in diameter, come in two varieties:

1. Non-foldable: When using non-foldable Intraocular lenses, the surgeon will make a long incision on the side of the eyem, and place the lens into position.
2. Foldable: When usinf foldable intraocular lenses, the surgeon will make a smaller incision, then insert and "ungold" the lens within the actual eye itself.

Due to the fact that foldable lenses require a much small incision in the eye, healing is much quiker, with reduced astigmatism. This makes foldable intraocular lenses the choice of most modern cataract surgeons.

There are also three options for the actual type of lens you have implanted as well:

1. Monofocal IOL: This type of intraocular lens corrects the vision at one focal length, ie close, immediate, or far.
   
2. Toric IOL: The Toric intraocular lens corrects vision for those suffering with astigmatism.
   
3. Multifocal IOL: The multifocal intraocular lens corrects vision for all distances (near, immediate, and far), in much the same way that mutifocal glasses work.