In many ways, the terms can be confusing. IOL means intraocular lens, and strictly speaking, an IOL is any artificial lens that is implanted in the eye. However, IOL has come to be accepted as the artificial lens that is implanted in the eye after removal of the natural crystalline lens or cataract. In other words, the IOL replaces the original natural lens. This type of IOL is mainly used in the treatment of cataract.

ICL refers to the Visian implantable collamer lens, which is a type of phakic IOL. A phakic IOL is an artificial lens that is implanted in the eye in front of the natural crystalline lens. Phakic IOLs are mainly used for the treatment of refractive error, such as high myopia. You will still be able to focus for both near and far is because you still have your natural crystalline lens.

The main problem with phakic IOLs is damage to the natural crystalline lens causing cataract. Most of the patients that I've seen with phakic IOLs already have some form of early cataract and it's only a matter of time before both the phakic IOL and cataract need to be removed. There are also other potential complications, such as elevated eye pressure and endothelial cell loss. Unfortunately there is a lack of data on the effect of phakic IOLs beyond 10 years, so we don't know how they affect the eyes in the long term.

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