Myopic glasses or sunglasses?
Myopia glasses recommend Oakley, global No.1 sports glasses brand, do short-sighted glasses is also good, and then Rayban
The sun glasses choice more, Oakley/Rayban has to do, the major luxury brands have to do, Prada, Chanel and so on, this is about to see your own love, and luxury brands are authorized, most of them are Luxottica, from design to manufacturing to sales
The role of myopia glasses is to correct vision, you can clearly see distant objects. In order to make the eye ciliary muscle maintain certain regulation ability. Because the distant light is not focused on the retina, resulting in visual object is not clear, while wearing glasses, you can get a clear image, so that the corrected visual acuity.
Myopic glasses are highly effective in the prevention of complications due to high myopia, such as retinal detachment, vitreous opacity, cataract, glaucoma, nystagmus, etc..
Spectacles for myopia are concave lenses. Erect a concave lens and the image is always smaller than the object, the virtual image, a concave lens is mainly used for correcting myopia. Myopia is mainly due to the lens deformation, resulting in a premature collection of light in front of the retina, a concave lens has a divergent light and concave lens into a narrow, upright, the virtual image, the image distance becomes longer, just fall on the retina. 
Degree of glasses: the refractive strength of glasses is usually expressed by degrees. A diopter (dioptre) equal to 100 degrees for the average person or an optical shop, that is, D 1 in a non Chinese speaking country (where the D is Dioptre, not the degree Degree). The more serious the vision problems are, the more lenses are required and the lens thickness will be higher.
First appeared in Italy, Florence, in 1289, Spina was said to have been invented by an optical scientist named Armato and an Italian who lived in pisa. Benjamin Franklin, an American inventor, suffered from myopia and hyperopia. He invented the near sighted glasses in 1784. In 1825, the British astronomer George avery invented to correct astigmatism glasses. Some people think that the Chinese invented glasses before 2000. Glasses appeared in the middle of Ming Dynasty in our country. Ming Tian Yiheng in “stay green rizha” 2 “thick” cloud: “every article, asthenopia, do not know the details, the head cover, the spirit is not scattered, Ming letter strokes. The damask silk used together, tied at the back, everyone does not know, move over to ask. I said: This is cloudy.” The thick first name.
Image and physical data exist Chinese not many early glasses. Chinese History Museum painting “Nandu Ming Tu” (fan club scene depicting Ming Yongle scenes of life in Nanjing city people) one old man wearing glasses. In the Qing Dynasty, Zhao said that glasses were introduced into China during the Ming dynasty. Qing Jiaqing glasses has gained popularity, Zhang Ziqiu continued in “all doors Zhuzhici” cloud: “everyone myopia wear glasses, with distinct depth system. Rao Yangmu light and clever, to buy by the genus epigenetic.” The words “Li Guangting Qing Xiang Yi” records, ancient Chinese glasses twelve to divide according to the underlying reasons depth scaling.
Since the invention of lenses in thirteenth Century, crystal glass has been used to grind lenses. China uses crystals besides crystals and uses artificial quartz. Later use glass lenses. In 1937, France invented a plastic lens called acrylic. Although it is not easily broken, it has poor clarity. An engineer in 1954 France Essilor inspired by the production of the aircraft cockpit material, thus the invention of resin lenses, since then, this lens will become the kingdom of the world extreme lens is still used today.
The lens type can be broadly divided into: the anti reflective protective lenses, lens color, color lenses, polarized lenses and photochromic lens five.
According to the nature of the focus: focus lens: Pingguang, three prism; single focus lens myopia, hyperopia lenses; lenses: bifocal lenses or optical lenses, progressive piece.
According to the nature of the function: visual correction: refraction, abnormal regulation, amblyopia, mirror.
Protection: prevent harmful light, control visible light (sunglasses), and prevent harmful substances (goggles).
According to material classification: natural material, glass material, plastic material
This lens is coated with a thin layer of magnesium fluoride, to prevent light reflection, let you see things more clearly and is not affected by the light interference. To check if your glasses are actually using anti reflective lenses, you can focus the lenses on the light source. If you see the purple or green reflections, it means that the lenses do have anti reflective protective films.
Also known as the “dye lens”, that is, in the process of making the lens, coupled with some chemicals, so that the color of the lens, used to absorb specific wavelengths of light. This is the most commonly used lens type of sunglasses.
This film has the same effect with the eye lens color, only made in different ways, it is the color painted on the surface of the lens, the most well-known is the “cascading color lens”, color is above the deepest, then gradually shallow down. The general prescription sunglasses are processing lenses to paint the way.
In order to filter the sun in the water, land or snow on the equal direction of the glare of the light, the lens to add vertical special coating, it is called polarizing lenses. Most suitable for outdoor sports (e.g., at sea, skiing, or fishing).
Also known as light-sensitive color lenses, or color film, with the intensity of the sun and change the color. Usually gray, tea, red, blue and so on. Generally used gray, gray because of the color, through the lens to see the object color is more dim, and does not affect the original color. The utility model can be used as a sunshade, and is suitable for people working outdoors. The color film on the market only has two colors: grey and tea
Compared with spherical lenses, it is thinner, and the peripheral vision of the center point is clearer than the spherical surface, reducing the difference of the surrounding areas, and helping to control the growth of myopia.
Contact lenses, as the name suggests, are wonderful in invisibility”. The term “corneal contact lenses” refers to soft contact lenses. The utility model has the function of correcting the eyesight of the common glasses, and relieves the inconvenience caused by the frame glasses. But the requirement of health care is higher.