Monovision

People over 40 years often face the condition known as presbyopia and need to use reading glasses or bifocal glasses. However, some people find it difficult to adjust to bifocals and others consider reading glasses to be an inconvenience, so another option, known as monovision, is available for some people with presbyopia. The chief advantage of monovision is the freedom that it provides from reading glasses. Monovision makes it possible to repeatedly change the range of focus, without having to constantly remove or add corrective lenses. This can be particularly useful for people who change their focus frequently - particularly teachers, public speakers, salespersons, and people involved in the performing arts.

How do we correct eyesight with monovision?

Monovision is an alternative for LASIK patients by doing LASIK and creating a different focal range of vision for each eye.

If a person has less than two diopters of nearsightedness, one eye can be surgically corrected to provide clear vision at a distance, and the other eye can be left uncorrected for near vision.

People with greater amounts of near-sightedness may have one eye corrected for vision at a distance (the completely correcting the near-sightedness will be done in the dominant eye), and the other eye undercorrected to provide better close-up vision (leaving the small amount of near-sightedness in the non-dominant eye to allow for near vision).

The dominant eye should be able to see well at a distance, but not so well up close, while the non-dominant eye should be able to see well enough up close to allow reading, but not as well in the distance as the dominant eye. When both eyes are used together, both reading and distance vision should be comfortably usable. This will help the patient to see well both in the distance and up close, without the use of spectacles.

Monovision may result in decreased depth perception without the use of corrective lenses, so some people with monovision elect to wear corrective lenses for activities such as, driving at night or dimly-lit environments. Also individuals, who read for long periods of time, may need to use reading glasses.

How does monovision work?

Our brain is constantly processing information from our senses. Visual information is processed as well. Prior to the onset of presbyopia, accommodation allows the eyes to change focus so that the object of our interest and attention is clear, while those objects at any other distance are blurred; our brain then gives attention to the clear object in which we are interested in whether it be in the distance or up close. With monovision, a person must "learn" to attend to visual input depending on the focal distance of the object. For most people, who proceed with the treatment, there is a period of adjustment of about two to four weeks. As with most vision correction processes, there are some individuals who will not adjust to monovision. For the patient considering refractive surgery, it is best to determine one's ability to adapt to monovision in advance.

How to conquer adjusting with monovision ?

There will be a lot of adjustment required in the early stage of monovison vision correction. The discomfort experienced in the early stage does not indicate that the patient made a wrong decision, but one be patient to allow for the period of adjustment and discomfort to pass.

How to adjust to your vision after monovision?

In the early stages (first 3 months) after surgery, you may have some vision problems such as the inability to properly focus both near and distant objects which may cause double vision, dizziness, nausea, pain when using the eyes and fatigue. The patients need to relax and give the eyes and the brain a chance to adjust and we encourage you to use both eyes simultaneously.

The adjustment period takes around 1-3 months. At this stage the ophthalmologist may need to prescribe temporary glasses for reading, until the eyes are fully adjusted.

Do you need enhancement?

After 3 months of adjusting and you still cannot overcome the monovision, (very few cases have been found) an enhancement procedure may be needed. At this stage, a discussion between our ophthalmologist and the patient is essential. The enhancement procedure doesn’t take long and we normally use the flap that was previously cut, using the laser again. After monovision you may need only one eye enhanced.

The enhancement process may be performed safely any number of times depending upon the thickness of the cornea in your eye. The doctor and patient will dicsuss the process thoroughly before the enhancement is done.