Surgically implanted lenses, also called phakic IOLs (intraocular lenses), are a new option for people seeking more permanent correction of common vision errors such as myopia (nearsightedness). These implants, which resemble contact lenses, are placed in either of two locations in the eye:

•  Between the clear lens in front of the eye (cornea) and the iris (colored portion of the eye), or

• Just behind the iris.
  Unlike traditional contact lenses, you cannot feel a phakic IOL in your eye - like a dental filling, which you know is there but has no sensation. Also, phakic IOLs require no maintenance.

Implantable lenses are a surgical alternative to LASIK and, in some cases, produce better vision than LASIK.

Both procedures alter the way light rays enter the eye, to achieve sharper focus. LASIK does this by removing tissue from the eye's cornea to change its shape. Implantable lenses function like glasses or contact lenses, except they do it from within your eye through the addition of an artificial lens to compensate for biological defects.

Implantable lenses are similar to the intraocular lenses (IOLs) used in cataract surgery. However, implantable lenses are placed in eyes that retain their natural lens, unlike in cataract surgery where IOLs replace a natural lens that has turned cloudy.

Eye surgeons may consider implantable lenses when other vision correction procedures aren't a good option, such as when a person has thin corneas or myopia between -3.00 and -20.00 diopters. With some patients receiving phakic IOLs, LASIK may be used as a follow-up to refine vision correction.
Two Food and Drug Administration-approved implantable lenses are available in the United States:

•  Verisyse (Advanced Medical Optics, Santa Ana, Calif. Marketed as the Artisan outside the United States by Ophtec, Groningen, The Netherlands) In 2004 the Verisyse phakic IOL received FDA approval for correcting nearsightedness in moderate to severe ranges of -5.00 to -20.00 diopters. Patients receiving this lens must be 21 years or older. Made of a type of plastic called PMMA, this lens has been marketed for a number of years in Europe under the trade name Artisan
   

 

 Verisyse phakic IOL.

 

• Visian ICL (Staar Surgical, Monrovia, Calif.) The Visian ICL or Implantable Collamer Lens received FDA approval for marketing in the United States in 2005. The Visian ICL is made partly from collagen, a biocompatible material. The ICL is foldable, which means smaller surgical entry incisions and potentially quicker recovery times (in about one day, like LASIK). FDA approval is for patients older than 21 who are nearsighted in moderate to severe ranges of -3.00 to -20.00 diopters. Many years before FDA approval, the Visian ICL was approved and marketed in many countries outside the United States, including Europe