The lens of an eye which is cloudy and no longer adequately transparent to light is called a Cataract. This causes vision to be blurry, hazy and colors to be washed out; much like foggy sunglasses that need to be cleaned. Once vision is sufficiently compromised, cataract surgery may be recommended by your doctor. The eye’s cloudy natural lens is removed during cataract surgery and exchanged with an intraocular lens implant (IOL). It’s much like replacing a dirty, brown-tinted camera lens with a clear replacement lens.
If you’re considerably younger than 50, and require cataract surgery, consider that any remaining natural ability to focus (accommodate) is immediately lost. After cataract surgery, you will require bifocals for near vision. For example, if a 30 yr old requires cataract surgery, removing this “young” lens that fully changes shape to focus on near objects and replacing it with standard implant with fixed focus may improve uncorrected distance vision but reading glasses or bifocals will immediately be required. This may be quite a lifestyle change! Conversely, older patients who require cataract surgery are already accustomed to bifocals and will still require them after surgery with a standard IOL.
Standard IOL’s have a fixed focus and are not designed to restore the eye’s natural ability to accommodate following cataract removal. Until recently, patients undergoing lens implant surgery had no other choice but a monofocal, or single focus IOL. Monofocal IOL’s implanted in both eyes generally provide excellent uncorrected vision if both IOL’s are powered for distance (infinity) and pre-existing astigmatism, if any, is corrected at the time of cataract surgery; however, patient’s typically remain dependent on spectacle correction for near and intermediate vision.