Monovision Contact Lenses for Presbyopia
Almost everyone who reaches the age of 40+ will notice a degeneration in their close-up vision. This condition, called presbyopia, is due to the lens of the eye losing its flexibility to focus, particularly on near objects. There are a number of treatment methods available.
In many cases, if farsighted vision is good, a pair of reading glasses is all that is required for close work and they can even be worn over regular contact lenses. Bifocal and multifocal contact lenses are another option. These have multiple zones on the lenses to correct vision for multiple distances.
You can also be fitted for different contact lens focus in each eye, a technique called monovision.
How monovision works
Monovision works by fitting one eye with a lens to correct distance vision (if required) and the other eye to correct near vision. (The lens for distance is usually worn in the dominant eye.)
The eye which sees distant objects clearly will see close objects slightly blurred and distant objects will appear blurry to the near vision eye. However, over time the brain learns to sort out the overall picture so with both eyes open, the result is usually clear vision at all distances. The eyes are still able to work together as a team and most people do not have any problem seeing clearly after the initial adjustment period. This same idea is used for monovision LASIK surgery where one eye is adjusted for near sight and the dominant eye is left for distance vision.
This is the basic principle of monovision but there are some slight variations:
Mini-monovision gives a less-than normal magnifying power to the near vision lens and is often the best solution for those who require sharp distance vision but do not do a lot of close work. For example, it would be a good choice for someone who does a lot of driving but very little reading or computer work. Reading glasses may be prescribed in addition for specific reading tasks, such as focusing on a menu. This type of monovision gives a better range of vision than just having corrective lenses for distance, but enhances far sight more than typical monovision.
This treatment involves wearing a single vision contact lens for distance vision and a bifocal contact lens in the eye for near sight. The result is sharper distance vision than standard monovision but with acceptable near vision without reading glasses. The bifocal lens can also be adjusted to provide sharper vision at arms length for such tasks as computer work.
The possible disadvantages of monovision
- Some people find that their distance vision is still slightly blurred while wearing monovision contact lenses.
- Others find that their near vision is not clear enough without reading glasses.
- In some cases, although the eyes are working together as a team, the binocular sight is compromised causing a loss of depth perception. This can be particularly problematic for certain people, such as athletes.
Monovision does not give perfect vision but the compromise is usually sufficient for most people.
Cost of monovision contact lenses
With standard monovision and mini-monovision, each eye has a conventional single vision contact lens which is one of the cheapest types of lenses available. Single vision lenses are significantly cheaper than their bifocal and multifocal counterparts, making monovision a less expensive alternative for many people. Modified monovision requires one standard lens and one bifocal lens, so while it's still cheaper than having to pay for a pair of bifocal lenses, it's more expensive than the other forms of monovision.
However, the fitting of monovision contact lenses is more complex because just a slight change to the contact lens in either eye can make a significant difference in the resulting vision, and each modification of lens power will require several days of adjustment time before vision can be evaluated. Therefore, the first appointment will take longer and more follow-up visits may be required than for a standard contact lenses, resulting in increased cost. Expect the initial fitting fee for monovision to be significantly higher, as much as double the cost of a standard contact lens fitting.
Bookmark This Page