Monovision Problems

Most people above 40 years of age develop presbyopia, a condition characterized by blurred near vision. It occurs with age, as the crystalline lenses of the eyes gradually lose their elasticity and ability to bring close objects into clear focus. This leads to difficulty in reading and focusing on near objects. The technique of monovision requires a person to wear near vision contact lens on one eye and, if needed, distance vision contact lens on the other eye. Monovision problems occur at the initial stage when you start wearing the two different lenses; not everyone can adapt well to monovision.

How Does Monovision Work?

All of us have a dominant eye and a non-dominant eye. While looking at distant objects, we actually use the dominant eye more than the non-dominant eye. Our brain processes the visual signals coming from the dominant eye. Therefore, if the non-dominant eye is fitted with a near-vision contact lens, our distance vision will not get affected much. If needed, a contact lens can be worn on the dominant eye to correct distance vision. Through this arrangement, the brain gradually learns to use the distance focused eye for distance vision and near focused eye for near vision. It takes about 1 to 2 weeks to adapt to this different way of wearing contact lenses, but some people may require a month or even more.

Before going in for monovision laser eye surgery, your ophthalmologist will always recommend you to first wear monovision contact lenses, to see whether or not you can adjust to the arrangement comfortably. If you are unable to adjust to it, surgery is best avoided. Surgery once done will be permanent and difficult to reverse.

Issues with Monovision

Problems with monovision arise because it basically hampers or compromises binocular vision. Binocular vision is the ability of both eyes to work together to achieve proper focus, depth perception and range of vision. Through the technique of monovision, the two eyes have to perform two different functions independently. It takes time for the eyes to start working as a team again. Till that happens, the person undergoing monovision experiences some loss of depth perception and blurring of vision.

Monovision generally causes blurred near vision because only one eye is fitted with the near-vision lens. If you require a very sharp vision to perform certain activities like reading fine print, then monovision will create a lot of difficulty in focusing. You will still have to wear reading glasses to help in reading. Sometimes your distance vision will also suffer from lack of sharpness, because only the dominant eye is fitted with distance vision lens. You will face major discomfort while driving, especially at night, and the glare from headlights will only add to your woes.

You may also have difficulty with your intermediate vision. When focusing on distances further than 16 inches but closer than 15 feet, for instance, while viewing a computer screen, you will experience blurring. Some people (about 10-15 %) do not adapt well to monovision. They may experience a feeling of being somewhat "off balanced" or will develop eye-strain and frequent headaches.

In spite of all of these problems, lots of people suffering from presbyopia do give it a try. This is because monovision requires the use of single vision contact lenses, which are less expensive than bifocal and multifocal lenses. A new technique of monovision, known as modified monovision makes use of multifocal rather than single vision near lens and it is more effective. However, monovision doesn't always produce the desired result and cannot guarantee complete freedom from glasses. It may or may not work for you. Monovision problems are significant and you should discuss them with an eye doctor, before going for this treatment option.