How to buy prescription glasses online
Consumers should choose different styles of frames according to their age and professional characteristics. Because everyone has different face shapes, different interpupillary distances, and different diopters, the size of the frames should vary from person to person.
Lenses are divided into glass lens, resin lens, and PC lens, and you can choose according to your preferences. The glass lens has a stable refractive index, good abrasion resistance, and stable optical performance, but it is relatively heavy and easy to break. Resin lens with high light transmittance is light, safe, and not easy to break, but the surface is easy to wear. PC lens has a high refractive index, but the surface is easy to wear.
What color coating is good?
The purpose of plating anti-reflection film is to reduce the reflection of light. But because it is impossible to be completely free of reflected light, there will always be some residual reflection on the surface of the lens that causes the visible color. Someone asks which kind of these residual color is best. It does not have a standard actually. It is mainly based on a personal preference for color. More on the market at present is green color. However, these residual colors can initially help us to judge the thickness of the film: when the film is thin (the thickness is less than 139nm), the reflected light will show light yellow, and when the film is thick (the thickness is more than 139nm), it will show blue-green. The current multi-layer anti-reflection film thickness is about 0.3μm.
Benefits of Progressive Lenses
The lens looks like a single vision lens, with no dividing line between degrees. Not only is it beautiful in appearance, but more importantly, it protects the privacy of the wearer's age (for the wearer of reading glasses). There is no need to worry about showing the secret of the wearer's age by wearing the glasses. Because the degree is gradual, the replacement of the adjustment effect is increased step by step according to the shortening of the close distance. There is no adjustment fluctuation, which is not easy to cause visual fatigue. Clear vision can be achieved at all distances in the visual scope.
What are the benefits of memory metal frames?
Memory metal materials are inherently lighter than metal materials, which can reduce the pressure on the bridge of the nose and skin. The memory metal frame is super elastic, so it never deforms, and it is so apparent that the temples on both sides of the frame line up with the ring. Because the bending can be automatically restored to its original state, the stability is comparatively strong. It has the benefits of high-temperature resistance, corrosion resistance, which will not cause skin allergy, and so on. It is a hypoallergenic lightweight metal for eyeglass frames that is strong and flexible. It is resistant to corrosion, making it proper for people who work, live or play sports in all kinds of outdoor weather conditions. The memory metal can be placed on the side of the face, making it easier and more comfortable to wear. The memory temples can freely rebound 180 degrees without deformation, making up for the insufficient effect of elastic β titanium. This kind of frame is not able to recover due to careless bending, and it has the function of restoring shape itself.
The Disadvantages of Aspheric Lenses
Here, we will show some disadvantages of aspheric lenses.
The aspheric lens has a relatively small light area. When the eyeball rotates around, it will blur a little when looking at the outside through lens edge. In other words, the visual range of the line of sight becomes smaller.
Human’s eyeball is spherical and the eyeball rotates to the edge. Through aspheric lenses, the objects near the eye appear protruding.
Are the glasses purchased online of good quality?
Always, there are some people who question online shopping, whether the quality of the glasses purchased online is up to standard. Then I have to ask, is the quality of the glasses bought in the physical store good? Most people do not have the ability to judge the quality of glasses. It can be said that they decide which to buy based on an inexplicable idea. Therefore, for those who do not understand glasses, the quality of the glasses purchased online is not a question we should consider. In my personal experience, there has been no quality problem with the glasses purchased online, and for the same price, the glasses purchased in physical stores are much worse than those purchased online.
Acetate frame and plastic frame
What is the difference between acetate frame and a plastic frame? Acetate frames are lighter and generally considered to be better than plastic frames. Acetate is known for its hypoallergenicity, so it is a popular choice for people with sensitive skin. Unlike some plastic or metal frames, they can cause allergic reactions.
- The manufacturing process makes the plastic frame more brittle than the acetate frame.
- If the temple does not have a metal bracket, it is difficult to adjust the plastic glasses.
- There are fewer choices of colors and patterns for plastic frame
However, you will notice that acetate frames are generally more expensive than ordinary plastic frames. Spectacle frames are daily necessities that we use for a long time. Therefore, durability is essential, and the life span of the acetate frame is longer.