The easiest way to test the prescription of glasses is to look sideways at the light, and the aperture is about 50 degrees. The following is the knowledge you need to know when wearing glasses.

Each type of lens has different characteristics, and the diversification of varieties and functions makes it difficult for consumers to choose. Which one to choose is reassuring? First of all, when choosing a lens, it depends on whether it meets the standard, and the lens is tested for various functions, such as the degree of damage to the cornea of the lens, the process of grinding the lens, the material used, the moisture content of the lens, and the air permeability.

  Secondly, the degree, size, material, and use time of the lens should be paid attention to.
The size of the lens is generally determined according to the size of the black eye of the wearer. People with larger black eyes should choose larger lenses, and people with smaller dark eyes should choose smaller lenses.

  People who often work in the sun can choose lenses with UV protection. Generally, people who are prone to allergies, people who are often in contact with cosmetics, and people who are often in dusty environments are more suitable for wearing disposable contact lenses.
frame. For people who need to wear glasses, the choice of frames is very important. When choosing glasses, consumers should not only consider the shape of the face, bridge of the nose, and the distance between the pupil and the glasses, but also coordinate with the skin color and hair color, so that they can wear them with temperament and demeanor. Generally speaking, people with wide faces should not use small and narrow frames, and people with long and thin faces should not use wide frames.
  For children, it is best to choose a plastic frame, and it is advisable that the frame can fit the nose. For some consumers with high myopia and high hyperopia, due to the high diopter, they should generally choose a small frame, and the smaller the lens, the better.
Commonly used spectacle frames are as follows: plastic frames, metal frames, nylon wire frames. Compared with frames, there are much fewer types of lenses, but its pros and cons are the decisive factors to measure the quality of a pair of glasses, so consumers must be cautious when purchasing lenses.
 Glass lens: Wear-resistant, but relatively speaking, its weight is heavier than lenses made of other materials, and it is also easy to break. Polymer resin lens: This kind of lens is lighter than glass lens, impact-resistant and not easy to break, but its hardness is lower, so it is easy to fluff and scratch.
To measure the quality of a pair of spectacle lenses, in addition to the material, it depends on the refractive index of the lens. The higher the refractive index, the thinner the lens and the higher the price.