Contact lenses how to choose the right way?
There are five types of contact lenses:
Rigid lenses. This version of the lens is most suitable for people with uneven cornea and astigmatism. Such lenses are designed for long-term use, but have their drawbacks. The first drawback is that while you get used to them and can feel comfort, it will take several weeks. The second disadvantage is that for oxygen they are almost impermeable, so they should be worn for no more than 20 hours.
Lenses are stiff , but oxygen penetrates through the eyes more freely. Significantly improved vision due to this (although use up to 5 years) and while as soft lenses they are comfortable.
Soft lenses very well pass oxygen. Because of the high water content in soft contact lenses, many people adapt from almost the first days of wearing them. Such lenses correct hyperopia and myopia, but astigmatism does not correct.
Soft contact lenses designed for prolonged wearing. Due to the very high level of water content in such lenses, they can be removed without wearing for up to a month. But they, unfortunately, increase the risk of infection, since the lens that is contaminated remains for a long time on the eye.
Soft lenses that are designed for short-term use. This kind of soft lenses is special, which every 2-4 weeks change. Such lenses are becoming more popular lately. Purified in the same way as soft ordinary lenses.
The latest advances in the technology of cleaning and manufacturing different types of contact lenses make it possible to carry them to a large number of people. But even modern and very new contact lenses do not solve all problems with vision and still some people do not fit. This happens because of very sensitive eyes or special individual optical requirements.
Many oculists do not advise children to use contact lenses, because they can damage the eye when they wear or remove lenses. Also, in dry climates or in dry air, you can feel contact lenses as "sand in the eyes." There may also be an unpleasant sensation when you are ill with a cold, because your eyes are watering all the time, or vice versa, are excessively dry, due to the drugs being taken.
There are also such cases that during menstruation in some women, lenses cause intolerance temporary either during pregnancy or taking contraceptives, as the chemical composition changes in tear fluid. People who work in an environment with chemical contaminants, dust and other irritants entering the air sometimes get tiny particles of these irritants under contact lenses, which causes discomfort. In such cases, goggles must be worn.
Complications associated with contact lens wear affect about 4% of their owners annually, and can disrupt the eyes' mucosa, tear film, layers of different corneas, and even the eyelid. Studies carried out by scientists on the side effects of wearing lenses for more than 5 years have shown that such people may have such consequences as an increase in curvature of the cornea, a decrease in the thickness of the cornea and superficial disturbances.Before touching the eye of contact lenses, you should carefully wash your hands with soap, which does not contain allergens and moisturizers.