Multifocal lenses - what is it?

About what it is - multifocal contact lenses - people of middle and older age know better. They represent a good alternative to ordinary glasses and are intended to combat presbyopia - age- long - sightedness . Because of the ailment, the lens loses its elasticity, can not change its shape, which leads to a visual impairment.

What is a multifocal lens?

The simplest contact lenses are bifocal. They have only two optical zones. The latter are clearly distributed: one is intended for sight near, the other is far away. The best multifocal lenses are improved. They can be compared to the most progressive glasses. They have several zones of different optical power, which provide smooth transitions. That is, a person in multifocal lenses can gradually move from reading a small font in a book located directly in front of the face, to viewing an object that is at an impressive distance.

Implantirovan multifocal lenses, you will forget about a lot of problems. First, visually improved. Secondly, you do not have to carry a few different pairs of glasses. Thirdly, the correction will be held loyal and very comfortable for the eyes.

Along with these advantages, there are lenses and disadvantages:

1. It's not easy to get used to them.
2. Multifocal corrective lenses are an expensive pleasure. However, you can always choose a design easier.
3. During the period of addiction, so-called jumps of sight can be observed: in the morning it becomes vague, and closer to the night, on the contrary - it improves.

The main types of multifocal lenses

There are three main types of lenses:

1. Variables bifocal - the most simple and understandable. Below them there is a zone of near vision, and above - a distant one. The upper and lower zones are clearly delineated. And so that they do not mix and damage the eyesight, the lens should be stable.
2. In concentric bifocal lenses, the zones of vision are annular, and they alternate. The design of lenses differs depending on which zone is located in the center.
3. The most difficult are aspherical multifocal lenses for glasses. In them, the refractive power of light varies from the center to the periphery. They are suitable for all people with presbyopia, except those who need a big difference between near and far sight.

How to choose multifocal lenses?

Of course, you need to do this only after consulting a specialist and a number of examinations - the cornea parameters are determined: optical pachymetry, asphericity index, the location of the pupil center, its curvature, diameter. In addition, the evaluation of the retina and visual fields is made, objective and subjective refraction at different distances is diagnosed.

Modern lenses are made from a special silicone-hydrogel material that passes oxygen and contains a sufficient amount of moisture. They are soft and hard. Like conventional spherical, multifocal lenses can be daily, routine and traditional replacement. As a rule, the most suitable lenses are made to order.

Selection of the necessary lenses is done in several stages:

1. Checking the eyes of an ophthalmologist.
2. The choice of the most suitable type of lens.
3. The required step is a test fitting. The patient must understand that he feels comfortable with those or other lenses and actually sees better.
4. No less important is the stage of training. The specialist should tell you how to properly wear lenses, how often they need to be changed, which are the basic tips for care .