I believe it can be both. In cataract surgery, the eye's lens is removed (because it has gone cloudy) and replaced with an implantable lens. IOLs can also be u

I believe it can be both. In cataract surgery, the eye's lens is removed (because it has gone cloudy) and replaced with an implantable lens. IOLs can also be used in myopia. The implantable lens is placed in front of the natural lens to correct the near-sightedness, like a contact lens but INSIDE the eye. The natural lens is left intact so you don't lost the ability to focus close up (accommodation). There are also accommodating lens implants, which are pretty new. So a cataract patient can regain their ability to focus close up.