Monovision Theory
Monovision contact lenses are designed for patients who suffer from presbyopia. According to the American Optometric Association, presbyopia occurs in people who are over the age of 40 and is the result of patients struggling to bring nearby objects into focus. Although it is part of the natural aging process, presbyopia can be very difficult for near-sighted people, who have trouble focusing on things far away. With monovision contact lenses, the patient wears one lens designed to aid in close-up vision and one lens designed for seeing things far away. The brain will learn to use the eye with the distance lens for faraway objects and the lens for close-up vision for near objects. Monovision contact lenses give the patient the ability to see objects that are near and far away by ensuring that at least one eye is able to project a clear image to the brain for all distances.
Mini-Monovision
One of the problems with monovision lenses is that they can make far-off objects appear less sharp and in focus because of the different lenses in the two eyes. For patients with this problem, according to All About Vision, doctors can use a tactic called mini-monovision. With mini-monovision, the lens designed for close vision is less powerful. Although this means that very close objects will not be perfectly in focus, by decreasing the difference between the two lenses the optometrist can minimize the blurriness of faraway objects. This form of monovision works well for patients who have more trouble seeing far away objects and do little close-up work.
Modified Monovision
Modified monovision is another solution for patients who find standard monovision makes some objects blurry. All About Vision explains that with modified monovision, one eye receives a distance lens. The other eye, however, gets a bifocal lens, which has some portions devoted to distance vision and some to near vision. This helps improve distance vision but also provides patients with the ability to focus on near objects. These bifocal lenses can even be designed for work that is arm's-length away for patients who need help when using a computer.
