Intraocular lenses & permanent implantable contact lenses
For some people with poor eyesight, permanent implantable contact lenses (ICLs), often referred to as intraocular lenses (IOLs), can replace the need to wear glasses or use standard contact lenses to correct their vision.
What are implantable contact lenses?
The natural lens in an eye focuses light rays on the retina in your eye. If the lens cannot create a focus point directly on the retina, vision in that eye will be blurred. When people with blurred vision wear glasses or contact lenses to correct their vision, they are basically placing artificial lenses in front of their eyes to bend light rays so they fall on the retinas.
Implantable contact lenses work in the same way but they are placed directly into the eyes. They are made of a clear synthetic plastic and remain permanently in the eyes, although they can be removed at a later date if necessary. The type of plastic used depends on the lens, but it will be compatible with the body so there is no risk of rejection.
There are two surgical procedures for implanting these lenses:
- Phakic intraolcular lens (PIOL) implant – the contact lens implant is placed in front of the natural lens. 'Phakic' refers to the natural lens - just behind the pupil - or it is attached to the iris, just in front of the pupil.
- Refractive lens exchange (RLE) – the natural lens is removed and replaced with a contact lens implant in the same way that a cataract is removed and replaced with an artificial lens by surgery.
Why choose implantable contact lenses?
Glasses don't provide peripheral vision (being able to see things to the side), and some people find them a nuisance to wear - they get easily smudged, mist up when there's a contrast in temperatures, can be uncomfortable to wear and can get knocked about, especially during sports or other lively activities.
Standard contact lenses are better at providing peripheral vision and don't have the same problems as those of wearing glasses, but they can also be uncomfortable such as if you have dry eyes. They involve a daily routine of putting them in, as well as taking them out and cleaning at night – unless you pay for disposable lenses – and eye infections are common if good hygiene practices aren't followed.
People who find glasses and standard contact lenses inconvenient can choose to have surgery to improve their vision. Laser eye surgery is one option, but it is not suitable for everyone, and unlike contact lens implants, it is not reversible. Laser surgery involves removing tissue from the cornea, but this is not the case for contact lens implants.
Implantable contact lenses don't have the same discomforts and inconveniences associated with wearing glasses or standard contact lenses, but the real benefit is that these lenses allow for a more convenient and active lifestyle. After they are implanted, the person with the implants does not feel them. Older people may still need inexpensive low-prescription glasses for reading or distance, for example, but more than 95% of people with contact lens implants are satisfied with the results.