EVO ICL (implantable collamer lens) is a sub-category of IOLs (intraocular lenses). All IOLs are surgically implanted. EVO ICL is an implanted phakic interocular lens that works with your existing natural lens. Other types of IOLs (not EVO ICL) are used after removal of the natural lens, as in Refractive Lens Exchange as well as cataract surgery and act as a replacement for your natural lens.