Presbyopia Correction through Monovision LASIK
PRESBYOPIA CORRECTION (MONOVISION)
Virtually everyone over the age of 40 is affected with age-related farsightedness, and need to use glasses for reading. Monovision is an alternative for those who are affected by myopia, hyperopia, and astigmatism, simultaneously with presbyopia. It is used to describe a treatment arrangement where one eye is treated for distance vision, and the other one for near vision. Although the LASIK procedure has greatly advanced over the years, it is limited in that only one permanent prescription can be put in the eye. It has not yet reached the point where a distance prescription and a reading prescription can both be applied, like bifocals glasses do. Monovision is a visual concept that works well for most, but not all presbyopic patients. Before a decision is made about proceeding with monovision, you may be asked to undergo a monovision trial with soft contact lenses. The goal of this trial is to simulate what your vision would be like after monovision laser vision correction. The trial should give you a good indication of whether monovision is a treatment arrangement that will suit your needs. Monovision works by completely correcting the dominant eye so that it is focused on distant objects, while leaving a small amount of nearsightedness in the non-dominant eye, in order to allow for near vision. The result is that the dominant eye is better focused in the distance and the non-dominant eye is better focused for near, and when both eyes are used together, reading and distance vision should be comfortably usable. Monovision will enable the patient to see reasonably well for both distance and up close, without the need for glasses for routine activities, such as reading price tags, menus, and cell phones.
ADJUSTING TO MONOVISION
During the early few weeks, your vision may not have adjusted to the new changes and you may not appreciate the full effect of monovision. Both eyes should be used together for monovision to adjust fully. You should not cover one eye at a time. You may experience blurry distance vision, and the eyes may fatigue very easily while reading. Some patients may complain of double vision, dizziness, nausea, and blurred vision, but this discomfort is normal in the early stages. These symptoms are not an indication that you have made the wrong decision. You may be prescribed spectacles during this time to help the vision until the eyes adjust fully. Often, this adaptation period can take 1 to 3 weeks, and symptoms usually decrease to nothing over 3 months.
SOME FACTS ABOUT MONOVISION
Undergoing monovision LASIK is advantageous in many aspects given the conveniences in everyday activities, but it also has drawbacks. It is a compromise and there may be instances when a pair of glasses will be of benefit. The distance vision may not be perfect, especially at night or in dim light, as one eye is better focused for near. Monovision typically works well for near activities for short periods. Reading for long periods may tire the eyes more easily. It can also affect depth perception slightly, so monovision is not recommended for pilots, taxi drivers, or anyone who has a license to drive commercial vehicles.
MONOVISION CAN STILL REQUIRE THE USE OF SPECTACLES ON OCCASION
Typically, patients do not need driving glasses for daytime. While driving at night however, you may need driving glasses to correct the mild myopia in the non-dominant eye. In instances when patients need to read or do craft work for long periods of time, reading glasses may help to prevent tiring. Using these glasses on occasion will not affect the eyes or alter the result of the vision correction.