About contact lenses
Decided, for some contact lenses? Good for you, but before you start to wear, you simply have to know something about these wonderful inventions.
The history of contact lenses began in 1500, when Leonardo Da Vinci, the discussions in the concept of contact lenses. Much later, in 1823 a British astronomer, discovered that eyesight could be achieved by the wearing of lenses directly to the cornea. The history of contact lenses, developed by William Fienbloom, which was created in 1939, the first contact lens made of hard plastic. It was on the eye with a kind of glue. In 1971, soft contact lenses were invented and in 1979, the permeable contact lenses first appeared. It was in 1983 that revolutionized the removable contact lens market. They were invented by a Danish manufacturer, sells its rights to Johnson & Johnson. The company started selling contact lenses on a large scale in 1987. They soon very popular and remained so until today.
Because it is a little familiar with the history of the contact lens is not enough. The most important information related to the situations in which it is advisable to wear contact lenses:
- To correct myopia, hyperopia, astigmatism and presbyopia. The main advantage of contact lenses is that they are properly anisometropy. A person is diagnosed when the eyes do not have the same distance point of refraction. Even if there are differences over 3 dyoptrics between the eyes, the correction may not be wearing glasses.
- For therapeutic purposes – as a substitute for bandage after surgery.
- For the aesthetic and cosmetic purposes.
There are a few steps to be followed if you decide to go for contact lenses:
-First of all, the medical consultation lasts about an hour to complete. There are a few things that need to be considered: the reasons that you decided to wear contact lenses instead of glasses and whether you can afford it or not.
-The next step is a verification that you have to take a test called “refractometry. Contact lenses are prescribed, along with the replacement glasses. A further series of medical tests will follow after them.
-The distance and diameter of each contact lens must be carefully measured .
-The examination of KL (which varies from 5 to 30 minutes) is required for the individual body of the curvature and the diameter of the contact lenses.
-The last step is the regular examination varies depending on the type of contact lenses.
Today we benefit from a variety of contact lenses, so you should have no problems in selecting the right one for you. There are:
PMMA contact lenses – this type was the first one and it was in 1960. The contact lens is made of very durable plastic, polymethyl methacrylate. The disadvantage is the fact that it does not allow oxygen in the air to the cornea. Instead, if you blink the tears from your oxygen reaches the cornea. This type of contact lenses is known for its durability and low cost.
Gas-permeable lenses – RGPs – so that oxygen in the air to go directly to the cornea. They are made of plastic in combination with silicone and fluoropolymers.
- Soft contact lenses made of plastic, the water as the most important attributes of flexibility and softness, and they allow oxygen to the cornea.
-Among the most popular types of disposable contact lenses are Acuvue lenses. The Acuvue contact lenses are for people with little or no astigmatism and should be replaced every two weeks. Some of Acuvue contact lenses are not just for daily use, but for the night to carry. The extended version of Acuvue contact lenses is made of materials that pass oxygen into even greater amounts than other types of contact lenses.
Depending on the number of times the contact lenses are worn, they can be divided into:
- Long lenses can be used for up to one year, but not continuously and
- Short-term objectives only for a time wear. It may be useful for a day and a night, but then they must be thrown away.
Today, more and more people have their glasses for contact lenses, because the latter are more comfortable and aesthetic. You can wear it in almost any situation: If sports, at work, in front of the computer, on the beach, swimming, etc. Not only that you healthier, but they can give you the eye color you always wanted.