The search for a treatment that can restore the eye’s ability to see at all distances has been one of the biggest challenges in refractive surgery. Traditionally, when patients develop cataracts, the treatment is removal and replacement of the cataract with an implanted intraocular lens, or IOL. The IOL has a prescription, much like a contact lens, and acts to provide focus at a given distance. Some patients who have cataracts in both eyes prefer replacing one cataract with a lens for distance vision and the other with a lens for reading. This is called monovision and gives a greater range of vision, but at a cost: the loss of depth perception.
Please click below for a brief but detailed animation.
Similarly, lens implants have also been used on patients without cataracts who have very high prescriptions in glasses, cannot tolerate contact lenses, or who are not candidates for LASIK or other laser vision correction options. This has traditionally worked very well, but again, without any option for correcting loss of near focus except for monovision.
These challenges have been overcome with the approval of several advanced-technology Intraocular Lenses (IOLs). The
Alcon Acrysof ReSTOR, and
eyeonics Crystalens are two of the latest improvements on lens technology that have been used to correct vision in patients. These lenses can be used in patients with or without cataracts who desire a life free from glasses not only for distance, but also for near work. Although the goal of each lens is similar, they have particular differences in how they achieve