The study found that nearly 30% of solar radiation will pass through the atmosphere, especially ultraviolet rays with wavelengths greater than 315 nm, which will cause the greatest damage to the eyes; therefore, good sunglasses can reduce light transmission, filter out more than 90% of visible light, and good protection. Here tell you how to choose sunglasses, I hope to bring you some help.

1. Brand and price
The prices of sunglasses of different brands are definitely not the same, like Ray-Ban, Oakley and so on. As the saying goes: "Buy good, don't buy expensive", Jiayu people suggest that you buy high-cost glasses, don't buy very expensive sunglasses for face, this is not worthwhile. Here Jiayu people have to remind that some people are greedy for cheap, and buy some very cheap but inferior sunglasses, although the price is cheap, but the damage to the glasses is really accumulated, so don't be cheap. If you buy qualified sunglasses, you have quality guaranteed and there is no need to worry.

2. Color
Different season, the lens color of the sunglasses you choose will vary. In summer, blue, green or brown lenses are generally used. In winter, the snow is strongly reflective. It is best to use yellow, brown or gray lenses. The stronger the light, the more darker of  sunglass' lenses.

3. Lens material and quality
The choice of lens material should be selected according to age, place of use, and preference. PC lens, also known as space lens, has excellent impact resistance. It is an injection molded lens. All safety glasses use PC lenses. Nylon lenses are also a good choice. Ultra-light weight, superior optical performance; glass lens hardness High, not easy to scratch, but easy to be broken. Resin CR39 lenses are light in weight and are not easily broken. Because most children are playful, it is often the case that hurt eyes by broken lenses. Therefore, it is best for children to choose PC lenses, or nylon lenses, or CR39 lenses, but not glass lenses. In order to reach the polarizing effect and filter out the reflection of sunlight, it is best to choose a polarizing lens. Also, 100% UV protection. The regular good lens surface is smooth and free of ripples, flaws, bubbles, and wear marks. Jiayu lenses are all with 100% UV400 protection, and pass CE, Australia and USA standards.

4. Face shape matching
Different face shapes, choose sunglasses that suit the faces, so that it looks good and comfortable. The fashion trend changes each year. Big size, small size, medium size, round shape, square shape, etc. each year, they are always changing.

5. Frame material
There are mainly three different frame materials, namely plastic, acetate, and metal frame. Plastic includes PC (polycarbonate) and TR90 (nylon) which are made by injection. Acetate frame is handmade. When it comes to metal frame, there are alloy, monel, stainless steel, aluminium, titanium and so on. Different frame has different cost. Not matter which kind of frame, the structure should be stable and even. And the sizes for Asian face and European face are different.