Contact Lenses

Corrective contact lenses are the overwhelming majority of contact lenses sold. While many wear contact lenses instead of glasses because they prefer the look without glasses, there are more practical considerations as well.

Some vision problems are simply not well treatable with glasses, but respond to contact lenses. This can include some forms of color blindness and physical problems with the surface of the eye as well as other issues such as aniseikonia. Another interesting treatment actually puts pressure on the eye to change the shape overnight, a treatment only applying to certain conditions.

Other practical concerns that encourage contact lens wear revolve around activities. Sports can often be problematic with glasses, but possible with contact lenses. Contact lenses don't get water streaked in the rain, and do not steam up when walking outside on a hot, muggy day.

On the other hand, there are also times when wearing corrective contact lenses is a bad idea. Sandstorms in dustier deserts, construction sites where mortar is being mixed and those places where tear gas are likely to be used are all places where you do not want to wear contact lenses. The particulates can get behind the lens, causing discomfort and scratching of the eye. Additionally, there are those who lack the patience to get used to wearing contact lenses.

There are several ways to classify contact lenses. One is wear time. Many contact lenses are only to be worn during waking hours. The users tend to find this too restrictive, even though wearing these lenses for long periods can be harmful. Manufacturers responded by creating extended wear lenses that can be worn day and night for up to six days. Now continuous wear lenses can be worn day and night for up to a month. This greatly simplifies matters from a user's point of view, and simply noting when to change the lenses on a calendar is far easier than daily cleaning rituals.

Another way to classify lenses is disposal time. Many lenses are single use, wear and throw away. These are common for those with allergy problems or people who only wear contacts occasionally. They are also useful for activities where loss of a lens is a substantial risk, such as swimming. The most common lenses are replaced every two weeks. Longer periods, up to a year, used to be more common, but are now unusual. The shorter use duration allowed thinner lenses and reduces deposits, making the corrective contact lens less likely to irritate the eye over long periods of time.

Bifocal Contact Lens |