Wearing the wrong glasses and getting accustomed to them, you make your organism (not only eyes) feel stress and pressure, because the human body is a single self-regulatory system.

Answer some questions:
- How often do your eyes become red?
- How often do you feel eye pain?
- How often do you feel headaches or dizziness?
- Do your eyes water in the bright light?
- Is it painful for you to watch while the bright sun is shining?
- Do your eyes get tired in artificial light?
- Do you need to strain your eyes in the rainy and foggy weather?
- Do you feel tired after the long reading or watching TV programs?
If you answered “Yes” at least 2 questions, you should think whether you have chosen your glasses correctly or not.

Though this chapter is named «Memo for those who wear spectacles», it would be useful to read it for those who do not wear glasses. In the age of information boom, when we get about 80% of all information through the eyes, the problem with the vision will concern to everyone sooner or later. To prevent irreversible changes is very important nowadays.

Now let’s start with some main glasses characteristics, which are very important while choosing glasses:
1. Optical characteristics:
- Pupillary distance;
- Refraction (diopter).
2. Spectral parameters:
- Absorption and transmission of visible light;
- Absorption and transmission of the invisible band of light.
3. Material of the lens.
4. The weight of lenses.
5. Break security of glasses.
6. Scratch resistance coating of lenses.
7. Resistance of the cover of the lenses.
8. Pupillary distance of the frame.
9. Weight frame.
10. Material of the frame.
11. Frame construction:
- Cast plastic;
- Metallic with coating;
- Metallic with fastening the lenses by the line;
- Metallic with fastening the lenses by the screws;
- The availability of hard and soft nose pads;
- The availability of springy hinge
12. Shape of the frame

And now let’s start with the rules:
1. Before ordering glasses, you should consult optician, and obtain a detailed prescription.
Inadmissibly:
- To order glasses after the computer check-up without further consultation with the optician;
- To order glasses on the same prescription constantly. The prescription must be no more than 2 years old!!!
We would remind you:
Bifocal glasses, which are very convenient to use, should be ordered only if they are prescribed by specialist!
2. It is necessary to know what materials were used to make your lenses. The determining factors are the weight, thickness, optical and spectral characteristics of lenses.
The lightest lenses today are the lenses made of optical polymers. They are more than 2.5 times easier than glass lenses, which is extremely important if you have a vision diopter 4 and above. In these cases, even if the frame is well-chosen, heavy glasses will move to the tip of the nose and this will have a pernicious effect on your vision and that’s why it is inadmissibly. Firstly, because the optical power of the lenses changes, secondly, glasses wearer feels pressure on the important reflexogenous area on the wings of the nose and cheeks, thirdly, breathing hampers, fourthly, a cosmetic defect may appear because of the shifting of the skin on the nose and under the eyes.
It is inadmissibly for children, drivers and elderly people to wear lenses made of optical glass because they are hazardous. We are often asked about the suitability of plastic lenses. The answer is: you need to know one simple rule - the lenses made of the optical polymer CR-39 are the only ones that satisfy all the standards and requirements of the glasses, they are easy, durable, non-defective and non-hazardous.
You must know that lenses made of optical polymer CR-39 have the best spectral characteristics. Why is this so important? There are so-called sun depending diseases, which are stimulated by the redundancy of sunlight (cataract, nebula, light burns of the retina and others). The redundancy of short-wave part of spectrum, that is ultraviolet and blue-violet spectrum, have a damaging effect on the eye, including the photoreceptors of retina, crystalline lens, cornea. Lenses made of optical polymer CR-39 contain so-called UV-absorbers, which prevent getting harmful radiation into the eyes.
3. When buying sunglasses and fashionable colored frames, you need to know exactly that they have UV-coating.
4. When you choose frame you should draw attention to the following:
The tendency to allergic diseases.
Mobility of the nose pads if they exist.
The size of ear arms must strictly correspond to the distance between the frame and the salience behind the auricle. The ear arms must not press on the temples and reflexogenous area behind the ear. In a large face it is desirable to select frame with springy hinge.

We hope that these few simple rules will help you to decide independently what good for your eyes is and to choose glasses more confidently.