Identify the lenses of discount glasses
Look at the overall package: let him show you the overall package of the lens. See that if the factory is in China, Shanghai, China, or Zhejiang, China, etc. Look at the anti-counterfeiting logo. It doesn't necessarily mean it's good. Check the production plant, address, news, etc. In short, lens judgment, for the average consumer, is difficult, but when you put forward these requirements, the store will at least think you are more professional.
Features of Beta titanium glasses frame
Beta titanium has better strength, fatigue resistance, and environmental corrosion resistance than pure titanium and other titanium alloys. The shape plasticity is very good, which can be made into wire and sheet, more lightweight. They are used to make glasses and can get more shapes and styles. It's the material for a new generation of glasses. Customers with higher requirements for style and weight can completely choose beta-titanium glasses. Because β titanium processing technology is higher than pure titanium, usually only large factories and brands will produce, and the price is higher than pure titanium glasses.
What Is Bifocal Lens?
Changes in vision seem to be related to age. Presbyopia, a common eye condition that occurs in middle age, causes changes in your eye’s ability to focus. But this condition can be corrected by wearing bifocal glasses.
Bifocal lenses are divided into two parts to accommodate two different prescriptions in one lens. One area of the lens will have one prescription (usually distance) and a segment in the lower half will have the other (usually near vision).
The bifocal glasses were invented by Benjamin Franklin, who solved his own vision problem by taking the lens from his reading glasses and distance glasses and cutting them in half. Then remade the cut lenses into a single pair of bifocals and put the distance lens on top and the reading lens on the bottom.
Is titanium alloy necessarily worse than pure titanium?
In the common case, the introduction of a titanium frame will have a detailed material label, what titanium and what material is it made of, such as titanium nickel alloy, titanium aluminum vanadium alloy, and so on.
The composition of titanium alloy determines the quality and price of the frames.A good titanium frame is not necessarily worse or cheaper than pure titanium.It is difficult to ensure the quality of titanium alloy which is very cheap in the retail market.In addition, titanium alloy is not to reduce the cost, but to improve the performance of the material.Usually, the memory frame on the market is made of titanium alloy.
Types of Adjustable Glasses
Adjustable glasses come in different types including adjustable reading glasses, adjustable focus glasses and adjustable focus reading glasses.
Adjustable reading glasses have an adjustable focal length and compensate for refractive errors. They provide variable focusing so you can adjustable them for desired distance and prescription. They are often used for reading because you do not need to adjust the position of your eyes.
Adjustable focus glasses offer an adjustable focal length. They are used to correct refractive errors including presbyopia. They provide variable focusing so as to adjust the glasses for seeing things close up or far away.
Adjustable focus reading glasses are the same as adjustable reading glasses. You can adjust the dials of the glasses so you do not need to reposition your eyes to see objects clearly in the near or far.
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.
Advantages of Plastic Frames
Plastic is usually called a plate, having no skin allergies. The price is relatively cheap. Colors and styles are diverse. The color is rich, rich in shape. The injection molding material is higher dimensional stability of the whole batch, fast processing speed, and low comprehensive cost. Material prices are lower. It has a certain flexibility. TR material has high transparency. With high flexibility, it can meet the needs of different sizes. Plate material surface hardness is high. They need no surface treatment, having noble texture, wear-resisting. Suitable comfort change can be made according to different face sizes. It is the most mature material used in eyewear products of international apparel brands.