Why do you need rimless glasses?
Traditional full-frame glasses can sometimes make your face look heavy, especially if the lenses are thicker. Rimless glasses can replace heavy frames without weight from the rims. This reduces the pressure on the nose pad, making your face feel lighter and more comfortable.
Parameters of lens material selection
Since the refractive index of the lens material varies for the light of different wavelengths, and white light is made up of various colors of light of different wavelengths, the dispersion phenomenon occurs when the lens refracts white light. The dispersion coefficient is an important index to identify the sharpness of lens imaging, which is usually indicated by Abbe number (Abbe number = dispersion coefficient). The larger the Abbe number, the smaller the dispersion, and vice versa, the smaller the Abbe number, the larger the dispersion, and the worse the resolution of the image.
Humans have been using glass lenses for about 300 years, and it was not until 1947 that the first resin lenses made of CR39 were produced. A big reason for using resin lenses is their safety, i.e. impact resistance. Only lenses that pass the Drop Ball Test are considered safe. Combining the above two parameters, we can compare different lenses.
How to determine whether progressive lenses are worn correctly?
Once your glasses are back from the lab, the optometrist will let you put them on for an audition and make final adjustments to make sure they fit. If the prescription is not in the center of the lens, it will make it difficult for you to see clearly. The key is that the lenses match the wearer's eyes, especially the pupils. Before ordering a new lens, the optometrist takes two measurements: pupil distance and fitting height.
Limitations of NXT lenses
NXT lenses made from Trivex can't be cut by means of traditional edge cutting ways, requiring certain edge grinders, which has caused some problems for retail stores. Therefore, now NXT lenses are more used in some glasses, like sunglasses, protective goggles, and so on.
How much does it cost to change the frames?
The price of changing a glasses frame is very different, from tens of yuan to thousands of yuan, mainly to see the quality of the glasses, material, and so on. Still, you should think about: the use of fixed a number of years of glasses if the glasses have wear and tear if it is worth to change.
John Lennon Imagine
The circular wire-rimmed glasses like these were made popular by the Beatles' idols in the 1960s and immediately became a favorite of hippies and music lovers around the world. This modern version has an ultra-light frame made of stainless steel that resists rust and corrosion. Flexible spring hinges and coated temples are very comfortable. For fans of retro-inspired accessories, the glasses are a favorite.
Are titanium glasses frames worth it?
In order to exert the flexibility of the material, the β titanium frame is designed to be mostly fine and delicate, and the style is limited by this. So the price of a pure titanium glasses frame is more expensive than the beta titanium frame, of course, the comfort is higher. Beta titanium has better strength, fatigue resistance, and environmental corrosion resistance than pure titanium and other titanium alloys. It has good shape plasticity and can be made into wire and sheet, which is lighter.
Because the texture of pure titanium frame is better, so it is more expensive than other frames, at least should the price reach more than 20 dollars, if the frame is only a few dozen dollars, then it must be fake and inferior. The most important thing to avoid buying fake products is to choose brands. For example, Seiko and other well-known brands rarely have fake and inferior products, so that consumers can be more assured to buy.