Some information about Eyeglass
All my human activity is based onthe results of the perception of the external world. A similar process takes place through the perceptual system of the body (eyes, nose, ears, nose, etc.). All signals are sent to the brain, which interprets them, and gives a command to the response. Naturally, not all the senses are the same, in terms of volume of perceived information, but importants for a total chain, as diversifying the sources and accuracy of the information received. Undoubtedly one of the most important in this list is the vision through which the brain receives 70 to 90% of the whole information of the external world. Naturally, this implies a rather complex structure of the visual system, a large burden on the eyes, and thereforeIT and the likelihood of the development of various pathologies (such as congenital or acquired). The most frequent case of a pathological process in the visual system, is the loss of visual acuity (nearsightedness, farsightedness, astigmatism, etc.). In order to correct these abnormalities are used widely known optical devices (accessories) - glasses. The main andx acting elements are lens size and shape depend on the level of vision correction or eye protection (sunglasses). By the way, you can buy in the store LensDay. In the manufacture of spectacle lenses used are two main groups of materials:
- Mineral glass . It consists mainly of silica (sand) which may be added various mineral compounds that increase the refractive index of a standard 1.523 up to 1.9. The higher the index, the lens can be thinner. The advantages of this type of lens are excellent optical properties and resistance to scratching;
- The polymeric organic compounds . Compared with organic lenses, plastic lenses are more stable udaropochny safe and have a low weight.