The discoloration principle of photochromic lenses
The fine grains of silver halide and copper oxide were melted into the glass melt of the lens blank material to produce the lens. When the lens is in the ultraviolet environment, the silver halide molecules will undergo a chemical reaction due to the ultraviolet radiation and decompose into silver ion particles and halogens. Because the silver particles are dark and absorb visible light, the lens gets darker. When the ultraviolet light is weakened or isolated, silver ions and halogens are recombined under the action of catalyst copper oxide to form silver halide, so the color of the lens gradually becomes lighter and transparent again. The discoloration mechanism of the resin lens is similar to that of the glass lens.
Square-frame glasses
This frame is usually reserved for working women and can be paired with a simple or slightly sexy look, with tall eyebrows and dark lipstick. If they are big-frame glasses, usually they are more popular with some star friends. Big frame glasses collocate energetic dress-up, making a person unexpectedly full of sunshine and affinity.
How to drive at night with glasses?
If you need to wear glasses while driving, you'll need special glasses when driving at night, because common lenses reflect oncoming lights, which produces a faint glare. This will reduce your visibility. It's OK to wear contact lenses while driving. As you get older, your eyes become more sensitive to glare. Ordinary sunglasses or goggles are only suitable for wearing during the day, driving at night will seriously affect the vision (national standards stipulate that light transmittance of night driving glasses must be greater than75%). Although the all-weather driving glasses can weaken the strong lights, the vision darkens and affects road safety which does not meet the national standards for driving glasses at night. You should choose functional driving glasses that can block strong light, glare and increase the field of vision. This can effectively reduce the glare of the car lights but can filter out the extra harmful light. When worn at night, it can soften the strong lights and make the vision clearer. In this way, the safety of drivers is ensured, the fatigue of eyes is alleviated, and the radiation damage of harmful lights to glasses is prevented.
What frames can you choose?
According to its style, the spectacle frame can be divided into full frame, half frame, no frame, and eyebrow frame, combination frame, etc. They each have their own characteristics, but have their own loyal fans, and give users more choice. It is recommended that consumers who like broad vision and light frames choose rimless or half-frame glasses. The young and fashionable people choose the ever-changing full-frame frames. There are also people who like ornamented frames, such as print flow pattern small carving, and so on, and these details on the treatment of different styles of glasses frames have the icing on the cake.
Size of the glasses frame
Children's glasses should have enough field of vision. Because children have different kinds of activities, try not to choose frames that will produce shadows and blind corners. If the frame is too small, the field of view will be smaller. If the frame is too big, it will be easy to wear instability, and weight will increase. So the frames for children should be moderate in size.
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Is there a standard for lens material selection?
No, again, according to your needs and budget. The materials of lens mainly include glass and resin, among which resin materials are divided into thermoplastic materials and thermosetting materials, respectively represented by PC and CR39. Different from the lens frame, the lens market choice is more uniform. And in recent years, resin lenses do better and better, most people choose thermosetting resin lenses.