What are the lenses?

For vision correction, except glasses, widelycontact lenses are used. The name is what they got because they are in direct contact with the eye. It can not be said that this is a recent invention, the brainchild of new technologies. We can talk about what lenses are today, but they were invented much earlier.

The history of the appearance of contact lenses

For the first time, contact lenses were described byLeonardo da Vinci as early as the beginning of the XVI century. In 1887, the first glass contact lens was delivered to a person deprived of eyelids to save the eye from drying out. The experience was successful - the patient had worn this lens for more than 20 years. In 1938, plastic lenses come to replace glass lenses. In the 50-ies of the twentieth century, polymer hydrogel was synthesized, which is still successfully used in the manufacture of modern contact lenses. Unique features of this gel were two: the ability to pass oxygen (the eye "breathes") and the ability to absorb and retain moisture, washing the surface of the eye. This gave impetus to the massive introduction of contact lenses in everyday life.

Varieties of lenses

Even a simple listing of what contact lenses are in the modern world will take a long time.

• Let's start with the simplest - one-day. They are exactly so called that they wear them only one day, after which they throw out, and the next day they put on a new pair.
• The next type is daily lenses. Such lenses are worn in the morning, and in the evening they are removed, giving the eyes a rest for the night. They can be used for two to three months, then they have to be changed for new ones, because the worn edges of the lenses can injure the cornea. In addition, during this time they appear on microorganisms and sediment, which makes the image cloudy, diffuse. When wearing these lenses should be done at least one "unloading" day a week, allowing the eyes to completely relax from the lens.
• There are permanent lenses of long wearing - silicone hydrogel, usually they are worn, not removing, for a very long time - up to 30 days.
• Decorative lenses change the color of the iriseyes. They are divided into color (overlapping the eye's own color) and shade (which simply make the natural color brighter). Tinted lenses should choose "tone in tone". Pale blue eyes with their help will become bright, slightly greenish will acquire a rich emerald color. But here to try to put on brown eyes blue ottenochnye lenses it is useless, for the result will be deplorable: the indistinct dirty-gray color appearance will not decorate. Colored and tinted lenses, in addition to decorative function, can also correct vision if they have such a function.

By orienting yourself in what kind of lens there are, you can make an informed choice.

Indications and contraindications

In some cases, wearing contact lenses isthe only way to correct the vision, which can not be corrected with glasses. Also a direct indication of their wearing is a too active way of life: sports (especially swimming, athletics, ball games) or work of this kind where glasses can not be worn (the glasses mist up or fog too fast).

When switching from glasses to contact lensesconsult with an experienced ophthalmologist, which lenses are best to choose: daily, permanent or none at all, if the doctor finds contraindications in the patient. Do not wear lenses to people with eye diseases, especially infectious, and after eye injuries. Sometimes such micro-traumas arise just in case of improper use of lenses. In this case, you need to let your eyes rest for two weeks and use glasses at that time.

Progress never stands still, and it's the same.concerns the market of contact lenses. Their variety is so great that lenses, which can be selected of different quality, from any material and in any price range, are able to satisfy the most demanding customers.