In order to create clear near vision, your eye
As a person ages, their eyes naturally start to lose the ability to successfully increase power by the eye, thus the process of accommodation can no longer take place. When this happens, it presbyopia is said to have set in. In most cases, this does not start to happen until a person hits 40 years of age and the first symptom is normally most noticeable as reading becomes more uncomfortable. A presbyopic eye will still be able to see some objects completely clearly, however some objects will start to blur. Essentially, the eye enters a fixed state of focus. This means that at certain distances the eye is perfectly suited to create a clear picture (many times the vision will even be 20/20), however at any other distance, the images will bur.
Before contact lenses were used as a solution to this problem, people were forced to rely on either bifocals or traditional reading glasses. However, there are a variety of different contact lens options available today. The two most popular are mono-vision lenses and multi-focal lenses. Regardless of what type of contact lenses you choose to use to offset presbyopia, the principle behind them remains the same.
The soft contacts that are designed to treat this rely on the principle of simultaneous vision. This means that light from distant, midrange, and nearby all enter the pupil at the same moment. It is important to note that it will normally take 1 or 2 weeks for the brain to fully adjust to this change. However, once it does, the brain will adjust and start process images properly to create a clear picture. While this is completely successful in most cases. Sometimes, a person will still have to compromise some of their vision (either near or distance). Many optometrists are warned to discuss the possible benefits and limitations to these types of contacts because while they are nearly as good as glasses, if not as good, they are not perfect. If you set your expectations to high, then you will likely be disappointed by the results.
Presbyopia is a common problem that will start to rear its ugly head once people pass 40 years of age. While it can hinder the ability to focus on objects that are up close, it is almost completely treatable. Instead of using traditional reading glasses, there are a variety of different contact lenses that have been proven just as effective to treat this condition.