Sunglasses have a visible light transmittance of about 20% and can absorb ultraviolet and infrared rays well. It also has a variety of colors such as light green, light gray, light brown, etc., used to protect in different occasions. Among them, light gray lenses have little effect on color recognition. Light brown glasses make the blue sky look darker and reduce the transmission of green light. Light green lenses reduce the transmission of red light.
Sunglasses not only have a wide range of varieties, but with the improvement of decoration and health care effects, their scope of use has become more extensive. As the time to update sunglasses can be rapid, fashionable men and women would love to have multiple sunglasses to match clothes to satisfy their pursuit of fashion.
How to Find Reading Glasses Strengths?
Some reading glasses also come with strengths. So, how do you know what strength reading glasses to get and how to find reading glasses strengths? The strength of all reading glasses is measured in dioptre, with units increasing by 0.25 dioptre depending on the power of the lens.
The reading glasses strengths range from +0.75 dioptre to +3.00 dioptre. Both lenses have the same power which is indicated by a permanent marking on the inside of the frame or with a removable sticker on the lens. So, you can find the reading glasses strengths of the glasses.
The important thing you need to notice is that when higher the number, the greater the power of the lenses is when choosing reading glasses. So, glasses with a marking of 1.0 are low power while those marking +3.0 are high powered.
How to buy prescription glasses online
Consumers should choose different styles of frames according to their age and professional characteristics. Because everyone has different face shapes, different interpupillary distances, and different diopters, the size of the frames should vary from person to person.
Lenses are divided into glass lens, resin lens, and PC lens, and you can choose according to your preferences. The glass lens has a stable refractive index, good abrasion resistance, and stable optical performance, but it is relatively heavy and easy to break. Resin lens with high light transmittance is light, safe, and not easy to break, but the surface is easy to wear. PC lens has a high refractive index, but the surface is easy to wear.
Why should the surface of the lens be hardened?
Compared with glass lens, resin lens has the characteristics of lightness, safety, and comfort, but resin lens friction with dust or gravel in the process of use, resulting in lens wear and forming scratches. These scratches in the center of the lens can interfere with vision.
Therefore, in order to improve the wear resistance of resin lenses, it is necessary to add a layer of anti-wear film to the surface of the lenses. This is the hard coating technology of the lenses, which is called Hard coating.
What are the advantages and disadvantages of bifocal reading glasses?
The advantage of bifocal reading glasses is a large field of vision, and they can be used with the same pair of glasses to see far, near. The cost is lower. But different areas have obvious intervals, and the appearance is not beautiful. The middle distance is fuzzy. They need to adapt to the period. Bifocal reading glasses lens is divided into two parts, and the degree of the two parts is not the same. The upper part is the mother of the flat area to see far, and the next part is the child of the reading area to see near. There is an obvious interval. The appearance is not beautiful. There is no transition area between two different areas, so its vision is fuzzy, easy to produce a 'jump image'. Long-term wearing will make people dizzy or fall down when climbing stairs.
Each type of store has its own characteristics.
Nowadays, the optical stores in the market can be roughly divided into professional optometry and optical matching stores, fast fashion stores, brand flagship stores, and stores in shopping malls. The benefits of fast fashion optical stores are fast commodity update frequency, and they follow the fashion trend, which can bring consumers quite more choices. The size of fast fashion optical stores is usually not large, so they will use an open showcase design. The color collocation should be able to catch the attention of consumers, to attract customers to make self-service selection and experience.
Are the glasses purchased online of good quality?
Always, there are some people who question online shopping, whether the quality of the glasses purchased online is up to standard. Then I have to ask, is the quality of the glasses bought in the physical store good? Most people do not have the ability to judge the quality of glasses. It can be said that they decide which to buy based on an inexplicable idea. Therefore, for those who do not understand glasses, the quality of the glasses purchased online is not a question we should consider. In my personal experience, there has been no quality problem with the glasses purchased online, and for the same price, the glasses purchased in physical stores are much worse than those purchased online.