WHAT IS PRESBYOPIA?
The lens in our eye acts like a focusing lens in a camera. When we are children, our eyes are able to focus on objects as close as our nose to objects very far away. As we get older, the ability to “focus” decreases. Typically, by the time we reach our forties, we will need reading glasses or bifocals to focus on objects near to us. This condition is called “presbyopia.”
CORRECTING PRESBYOPIA WITH CORRECTIVE LENSES
When nearsighted (myopic) people over the age of 40 are wearing glasses or contact lenses to correct their vision, they also experience presbyopia. Because the nearsighted eye has a natural focal point “at near”, many nearsighted presbyopes can remove their glasses or contact lenses and read or do close work comfortably. Many people who are myopic choose to wear bifocals to eliminate the need for removing and replacing their glasses.
Many presbyopic contact lens wearers choose to wear a contact lens on one eye that does not fully correct the myopia which enables that eye to focus on near objects, while the other eye focuses well on distant objects. This type of correction is called “monovision.”
MONOVISION WITH LASIK SURGERY
If you plan to have LASIK surgery to eliminate or reduce your myopia, you may still experience presbyopia sometime in your 40s. You will typically be normally sighted after the procedure, and you may need reading glasses for small print, like every other normally sighted person after age 40.
Many of our patients choose monovision for their surgical correction to eliminate the need for glasses even when they reach presbyopia. However, some patients are not comfortable with the difference in their eyes and prefer not to be left nearsighted in one eye. Some patients choose to be fully corrected for distance and then wear glasses only for reading or close work when they becoming presbyopic.
If a person chooses monovision, they may choose to have distance vision fully corrected at a later time.
Modifed monovision is also for people over age 40 who may beneft from some near vision, but not full near vision correction. Your dominant eye is typically fully corrected for distance. Your non-dominant eye is typically corrected for intermediate
vision. The benefit of modified monovision is that it gives you a better range of vision, retaining some reading and distance vision in the modifed monovision eye.
The benefit for patients in their 40s is to give them reading vision that will turn into intermediate vision as they age. For someone in their 50s or older, modifed monovision will give you only some intermediate vision. You should be prepared to use prescription reading glasses, as your eyes will be diferent powers and the drug store eyeglasses are only sold in the same power for both eyes.
TRIAL PERIOD FOR MONOVISION
Patients who have not previously tried “monovision” with contact lenses, may be asked to do so before deciding to have monovision with the LASIK procedure. This will give them the opportunity to experience monovision and contact lenses. This includes the cost of most contacts, as well as teh fee for the doctor to fit you. You may be asked to try the contacts for one to two weeks before deciding to have monovision with your LASIK procedure.