LASIK for Reading?
The natural aging process of the eye creates a condition called presbyopia. Presbyopia causes the unfortunate and inevitable need for reading glasses, bifocals, or trifocals. Presbyopia is also known as age-related farsightedness, but is unrelated to true farsightedness (hyperopia) because it is not the result of the eye’s shape, but rather the loss of flexibility in the lens and the muscles around the lens. For people that have never had to wear glasses, they will notice this change usually in the early to mid-forties and gradually graduate to reading glasses when holding things out as far as possible stops working to bring reading material into focus. Low lighting conditions can also make it harder to read.
While this change is starting to happen for people that are nearsighted (myopic) in their early to mid-forties, it may be less noticeable because the nearsighted eye uncorrected can bring things into focus. So, if you are myopic you may start lifting or taking off your glasses to read before you graduate to bifocals. If you are farsighted (hyperopic) and are in your early to mid-forties, reading becomes even more difficult and you may rely on reading glasses earlier than your peers or have your glasses adjusted to include bifocals. As you age, you may find yourself in trifocals to give you good vision at different distances.
There are currently no reliable and predictable surgery techniques or medications that will outright cure presbyopia, however there are a number of permanent and semi-permanent techniques to deal with the focusing changes and challenges caused by presbyopia. One of the more popular ways to work around presbyopia is with monovision correction. For many, monovision will reduce or eliminate the need for readers, bifocals, or trifocals.
The concept of monovision is very simple. One eye is corrected for near vision and the other eye is corrected for distance vision. The brain figures out which eye to use and when. How to achieve monovision varies, depending upon your current eyesight.
If you have never needed corrective lenses like glasses or contacts before, then a small amount of myopia can be induced in your non-dominant eye. The dominant eye remains uncorrected, as it already provides full distance vision.
If you already have less than two diopters of myopia, your dominant eye can be fully corrected for distance vision, and the non-dominant eye not changed, which already provides good near vision.
People with greater amounts of myopia may have the dominant eye fully corrected to provide good distance vision, and the non-dominant eye undercorrected to less than two diopters myopic for good near vision. A patient who is already hyperopic may have the non-dominant eye overcorrected into myopia, plus the dominant eye either corrected for distance vision or untouched.
Contacts or Surgery
Monovision can be achieved through contact lenses or through refractive surgery. Advanced iLASIK, LASIK, LASEK, PRK, and Epi-Lasik are all appropriate techniques to create monovision. Conductive Keratoplasty (CK) is another refractive surgery that can create this effect temporarily.
The chief advantage of monovision is the freedom it can provide from reading glasses. After a short time, the brain makes the vision changes automatically, without any conscious effort or awareness. Monovision makes it possible to repeatedly change the range of focus, without having to constantly remove or add corrective lenses.
As with many good things, monovision comes with some disadvantages. People with monovision may have some degree of decreased depth perception unless corrective lenses are used to fully correct the slightly myopic eye. They may also notice blurred vision in the “near” eye when glancing in the side mirror of their cars or when the vision in the “distance” eye is blocked by an object.
We highly recommend someone with monovision have a pair of glasses made that provide full distance vision correction for those situations where excellent distance vision and/or depth perception are desirable. For detail activities such as prolonged reading, have a pair of reading glasses made that provide balanced near vision. It may be possible to purchase an identical pair of readers with two different powers of correction, and switch lenses to provide the balance to full near correction with both monovision eyes.
Test In Contacts First
If monovision seems desirable, you can try to achieve the effect with contact lenses prior to surgery to determine if monovision is suitable for your individual needs and your ability to adapt. At the pre-operative examination we can simulate your vision and possibly prescribe contact lenses for a trial before proceeding with a surgical option. If you initially choose surgical monovision and subsequently become unhappy with it, enhancement surgery to fully correct the undercorrected eye and reverse the monovision effect is often an option.
If you are entering mid-life and are interested in monovision, you should discuss the matter with us at your complimentary consultation or at your pre-operative examination. We can sometimes simulate what your vision might be like. It is surprising how many patients adapt readily and happily to this vision option, however monovision is not for everybody and some people dislike its effect.