Those that wear contact lenses should be aware of important information that can help protect the eyes from permanent damage. There is mounting evidence that contact wearers should give their eyes some time away from contacts. The conventional wisdom is that people can wear contact lenses for 12-14 hours per 24 hour period but that once a week the eyes should have a rest from contact lenses. Experts agree that if contacts are worn for over 16 hours a day every day that eyes may become starved of oxygen. This means that over the long term the cornea could lose its transparency.
If the eyes do not get enough oxygen, tiny blood vessels in the eyes will start to become more apparent and new ones will develop. One of the concerning aspects about these blood vessels growing on the eye is that there typically will not be any outward symptoms of this occurring. It is a good idea to have your eyes examined regularly while wearing contacts so that if this occurs it can be monitored.
A recent Dutch study found that overnight use of extended wear contacts is a risk factor for contracting a serious eye infection called "microbial keratitis." This infection has the potential to blind. In the study, the researchers were focused on this rare bacterial eye infection and its connection to contact lenses.
The researchers concluded that the risk of microbial keratitis was nearly 20 times greater for people who use extended-wear soft contact lenses. The risk was 3 times greater for people who use daily-wear soft contact lenses. The higher risks of infection are attributed to the use of extended-wear lenses and the tendency to keep these kinds of lenses in overnight.
Years ago, hard contact lenses were made from a material that kept all oxygen away from the cornea. Because of this, tiny holes had to be made in the lenses. Next, the rigid gas permeable contact lens was made and this kind of contact allowed more oxygen through to the cornea.
The rigid gas permeable contact lenses of today are typically called hard contact lenses also. For those with astigmatisms these are an effective choice in contact lenses because they can be molded to correct the shape of the eye.
Soft contact lenses are made from plastics that are gel-like in nature. They are all gas permeable and they also come in many different levels of water content. This means that they allow different amounts of oxygen through to the cornea. Many people prefer soft contact lenses because they feel they are more comfortable.
If one wears contacts and also uses a computer daily, it is common for tears to evaporate and contact lenses to dry up faster. For this reason, people often use eye drops to keep the eye moist. Make sure eye drops are fresh and within product dates.