What kind of glasses are bifocals?
Bifocals are mainly used in presbyopia correction, providing presbyopic opticians with a clear vision for both near and far use in one pair of glasses. The bifocal lens can be divided into two separate areas, with the upper part of the lens providing clear distance vision and the lower part providing clear near vision. The two regions of the bifocal lens provide different refractive forces, and the difference between these two refractive forces is the reading proximal addition, which compensates for adjustment during presbyopic reading.
How to Tell If Lenses Are Plastic or Glasses?
If you want to know if your glasses are made of glasses or plastic, the safest way is to ask the optician from whom you bought the glasses. If you do not want to ask the optician, there are several ways to differentiate them, such as sound, weight, and temperature.
Lightly tap the lens against your teeth or your ring. If the lens emits a high, ringing tone, it is a glasses. On the contrary, the plastic will have a low thud like sound when tapped.
Glass lenses are much heavier than plastic glasses and glass lenses feel colder to touch while plastic glasses feel warmer since it is a better insulator.
After learning what lenses you have, it is time to show how to remove coating from glasses.
Refractive index of spectacle lens
It is generally believed that the higher the refractive index, the better the spectacle lens. Such spectacle lenses are relatively thin, and of course, the price is a bit expensive. When the refractive index increases, the direction of the light entering the lens will change greatly, the focus will move to the lens, the focal length will be smaller, and the diopter will become larger. In order to keep the diopter unchanged, it is necessary to reduce the curvature of the lens, that is, to reduce the curvature of the mirror surface, so that the thickness of the lens can be reduced. This is why the larger the refractive index, the thinner the lens is. Under the same premise of other things, the larger the refractive index, the thinner the lens, the lighter and more beautiful the lens, and the higher the price, but the larger the refractive index is not the better.
The role of the driving glasses
Good driving glasses can be very good to block high energy light, in the evening they can let more faint light enter into our eyes, really solving the problem of only blocking the light and not blocking the road. They have very good night vision function, and can better eliminate glare, better improve the vision of the driver. The driver can drive safely day and night. Strong sunlight improves visual clarity. They are special driving glasses and can brighten polarized light and improve driving safety. With unisex style, high-definition vision, comfort, and light. It can be used on rainy and foggy days and can be used by myopic people. It can effectively filter strong light and high beam lamps, and the long-term use makes you not tired. Both rainy and cloudy days can improve visual clarity. It can effectively prevent strong light, ultraviolet light, and glare is durable and can solve the problem.
What Are Progressive Lenses?
Traditional eyeglasses are usually single vision lenses with one prescription. Progressive lenses are multiple with three prescriptions in a pair of eyeglasses. Progressive lenses let you see comfortably at different distances, allowing you to see close, near, and far without changing your glasses. There are other kinds of multifocal lenses like bifocals and trifocals, but progressive lenses differ because of their smooth transition between prescriptions.
Bifocals and trifocals work similarly to progressive lenses and feature either two or three prescriptions in a pair of glasses. These lenses have definitive lines separating the prescriptions. However, progressive lenses don’t use these lines and allow you to easily transition between prescriptions.
Hence, in the following section, we will show you 6 different types of progressive lenses.
Choose Quality Merchants
Online shops are of all kinds, from different parts of the country. We need to find a professional and reputable shop, with the help of some small skills. For example, from the purchase of some users of the use of evaluation, store credit rating, store introduction, and other aspects, we determine the overall situation of the store and finally buy in this store.
The style of prescription glasses
Choose the material, and then choose the style. The width of the appropriate frame should match the distance between the two pupils to ensure that the eye can pass through the optical center when looking at things. Choose the right style according to your face shape. Generally follow the complementarity principle, such as choosing square frames for round faces and round frames for square faces. After choosing the frame, you should try it on for a while to see if the weight is appropriate and the style is suitable.