The focusing ability of the eye is measured in diopters. Cataract surgeries usually remove the natural lens of the eye and this causes the eye to lose around 18 diopters, which is equivalent to one-third of the eye’s ability to focus. This loss is usually compensated by the cataract surgeon through implantation of an artificial intraocular lens (IOL).
Over the years, with improvement in IOL technology, patients are able to get 20/20 vision after surgery but are still not satisfied. Most complain that they are not able to focus on objects as naturally as they could prior to the cataract formation. This has led the medical professionals to look beyond 20/20 vision to provide patients the perfect vision that they expect. It is possible to obtain better than 20/20 vision.
The reason behind patient dissatisfaction
Even though patients most often receive 20/20 vision, they experience inferior vision when they are subjected to contrasting light. Studies have shown that after artificial lens implantation, the patients have a change in contrast sensitivity. This sensitivity has now become the superior method of assessing effectiveness of vision, which has led the researchers look at spherical aberration (SA).
No artificial lens such as IOL, contact lens or eyeglass is perfect. The optic may be very precise at the center but it varies when it comes to the outer surface of the lens. With the variation of optics, the ability to focus also changes drastically. To make things even worse, SA is magnified in high-powered lenses such as IOLs with 18 diopters. The enlargement of pupils under dim lights actually exposes the visual system to more SA. Also, if the IOL shifts even a little, there can be a sudden loss of sharp vision as the IOL center is no longer aligned with the visual axis.
Aspheric IOL can give you freedom from this problem. The implantation of this IOL results in minimum postoperative spherical aberration. Most patients who undergo implantation of aspheric IOLs report crisp visual images and are extremely satisfied with the results. Crystalens is one such aspheric IOL which patients can opt for. This is an FDA approved IOL, which your cataract surgeon in Detroit would be able to safely use during your cataract surgery. The company Bausch & Lomb, which introduced Crystalens even claims that it has a zero spherical aberration. So, people who undergo cataract surgery can now experience greater quality of both distance and intermediate vision.