Even if you undergo LASIK and achieve perfect distant vision, you will still develop a condition called presbyopia, typically beginning between the ages of 40 and 50, where the near vision gets affected. This is due to aging. When this situation arises, you will need reading glasses to get near objects into focus.
Presbyopia is usually noticed when fine print starts to blur.
In the past and even today, the usual remedy is to wear reading glasses or special multifocal lenses (bifocal or progressive lenses) for presbyopia. But there are other options and surgical remedies for presbyopia for some candidates. One of them is performing Monovision LASIK.
What is Monovision?
Monovision refers to the vision correction practice of prescribing distance vision in one eye and near vision in the other eye. This situation is usually created by applying contact lenses to the eyes or performing LASIK or refractive eye surgery. One of the first effective surgical options for presbyopia correction involved producing what is known as “monovision” during LASIK.
How does monovision work?
Normally, both your eyes work together equally when you look at an object, to produce what’s called binocular vision.
However, you probably have a dominant eye that your brain tends to favour such as how we are either right-handed or left- handed).
Taking advantage of this “one-eye dominance” to produce monovision, where typically the dominant eye is prescribed a contact lens power for optimum distance vision and the other eye is fit with a contact lens that has a modified power to provide good near vision.
But one eye sees more clearly in the distance, and the other eye sees better up close. This is a very helpful technique for patients who are over 40 who need reading glasses and also need help for distance vision.
Who are good candidates for monovision?
The age and near addition of the patient matter, with lower addition patients (+1.25 to +2.00 D) being more successful than higher addition, more advanced presbyopic patients.
The visual needs and lifestyle of the patient must be evaluated when considering monovision. Individuals in occupations such as teaching, the performing arts, public speaking and sales, who desire the benefit of being able to change viewing distances constantly and still remain
focused, are good candidates.
Some LASIK surgeons will produce monovision in their presbyopic patients by purposely leaving the non-dominant eye slightly nearsighted so that these patients can see up close without glasses. This usually takes some getting used to, and there are certain situations where it would not be appropriate. However we need to evaluate the patient thoroughly as not everyone can become accustomed to monovision.
When surgery is performed, the desired outcome is typically the same as that for monovision contact lens correction; however, it should be remembered that the patient’s need for additional near correction is likely to change again with age.
Hence, we always recommend that is a good idea to try monovision with contact lenses or trial lenses first to be sure you can adapt to it before you opt for monovision LASIK.