Presby LASIK, also known as multifocal LASIK, is an experimental type of laser vision correction surgery that changes the shape of the eye’s clear surface (cornea) to establish different zones for seeing at near to far distances.
This surgery corrects presbyopia, which causes near vision to blur as the eye’s natural lens begins to stiffen, usually at around age 40. If you are nearsighted and have presbyopia, you may be able to see up close without your usual eyeglasses or contact lenses but not when you are wearing them.
How the Presby LASIK Procedure Is Performed
Presby LASIK also is called multifocal LASIK because it works on principles virtually identical to artificial multifocal lenses used to provide vision correction for presbyopes. With presby LASIK, laser energy reshapes your eye’s clear surface into different zones, such that light is bent or refracted differently in each zone. In this way, both near and distance vision can be achieved simultaneously.
Because presby LASIK still is in investigational phases, different approaches are being studied to determine how the eye should be shaped to achieve the best possible vision correction for presbyopes.
For people who are nearsighted and presbyopic, different configurations of eye shapes are being studied. In some cases, near vision correction is provided in the central zone of the cornea, and in others, near vision correction is established in the peripheral area.
Another method of presby LASIK adds what is known as aspheric corrections to the eye’s surface. Aspheric shapes are not perfectly round and are thought to help reduce vision distortions or aberrations that generally can be associated with vision correction.
Still other presby LASIK methods under investigation aim to provide customized procedures uniquely suited to the individual’s needs and lifestyle. If a person performs considerable close-up work, for example, the presby LASIK vision correction procedure might be adapted to enhance near vision in lieu of better distance vision.