Presbyopia generally occurs over the age of 40 and is characterized by a gradual loss of near vision. This condition is due to the normal aging of the eye and its progression is not affected when a surgery is performed to correct the distance vision.
When you are young the various parts of your eyes work together in harmony. Your natural lens makes subtle changes in shape, allowing you to effortlessly switch focus from far to near. This natural process is called “accommodation.” As you age your eyes becomes less efficient. Your lens can no longer make these delicate adjustments and you lose the ability to accommodate. Your vision may become dim or blurry when looking at things close up, colours may not be as bright and crisp, you may have difficulty distinguishing between colours of a similar shade (contrast sensitivity), and you may also experience difficulties seeing in dim lighting. In most cases these symptoms are the result of your eyes becoming less supple, less flexible and less efficient.
A Refractive Lens Exchange is a good option for presbyopia. In this procedure, the natural lens of your eye is removed, exactly the same as during cataract surgery, and replaced with an artificial Intraocular Lens (IOL). The IOL will correct refractive errors in your eye (nearsightedness/myopia, farsightedness/hyperopia) with a specific power or prescription that corrects your vision, similar to wearing glasses. A multifocal lens will decrease the need for reading glasses due to its ability to enable near, intermediaire and far vision.
However, it is possible to avoid the need of glasses by leaving some myopia in one eye which will result in concealing presbyopia. This technique is called monovision. In order to increase the success of the surgery, you will try it first with glasses or contact lenses to determine your ability to adapt to this vision system.