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| Vial Lenses | Vial contacts are lenses with a guarantee term up to one year that should be removed every night before a sleep. Lenses should be cleaned and sterilized every day. There are soft and rigid lenses.
 The first contact lenses appeared in the 17th century, only several hundred years afterwards they were used practically. Irritated eyes were a common phenomenon until 1971 when the first gas permeable lens appeared. Their main advantage was the penetration of “breathing” oxygen necessary for comfort and safety. The first gas permeable lenses were made in a soft material known as hydogel; nowadays there are soft lenses and hard oxygen permeable vial contact lenses. At the beginning of the eighties tinted lenses, extended-wear vial lenses and bifocal lenses appeared.
Rigid gas permeable contact lenses provide the entry of oxygen to the eye, besides they are easily handled and provide the better optical acuity. |
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