What Are the Disadvantages of Progressive Lenses?
In this section, we will show you some progressive lenses disadvantages.
1. You must learn how to see through the lens. Since there is no visible line in progressive lenses, you may need one or two weeks to learn the correct way to look through the lens.
2. Temporary vision distortions. The lower part of a progressive lens is magnified since it is designed for reading. So, when you look downward when stepping off a curb or walking upstairs, your feet may appear larger through the progressive lens so that it is difficult for you to gauge your step.
3. Progressive lenses are expensive than traditional glasses. So, when you purchasing the progressive lenses, you can compare several different optical stores. In addition, Koalaeye Optical, a professional glasses provider, offers various glasses including cheap progressive lenses, sunglasses, blue light glasses, and so on. Besides, it provides the free shipping service.
Glasses in a Day
With decades of experience in the optical business, it allows the fastest prescription eyewear service. Male and female frames are mostly imported from Germany, Italy, and France. All orders are shipped the same day they are received, including Saturday, ensuring your new glasses arrive quickly. The team assembles, packs, and ships your glasses at our Massachusetts facility on the same day you order them.
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.
What Are Single Vision Lenses?
What are single vision lenses? You may have the same question. Single vision lenses have only one prescription for a given distance. Most reading glasses and distance glasses have single vision lenses because they are designed for people who are difficult in seeing either near or far. Some people are using their single vision glasses for both far and near depending on their types of prescription.
You can choose to wear single vision reading glasses to correct your eyesight if you have trouble reading text on your phone or computer screens. You can also wear single vision glasses to help you make out traffic signs while driving.
Single vision lenses for farsightedness are thicker at the center than those for nearsightedness, which are thicker at the edges. And the single vision lenses generally range between 3-4mm in thickness. The thickness varies depending on the size of the frame and lens material chosen.
After learning some information about one lens glasses, do you know the benefits of them? So, in the following part, we will show you the advantages of single vision lenses.
Why are blue light glasses yellow?
The material of the lens makes it turn yellow. If it's just blue and the lens is yellow, that's the material itself. Blue light glasses can weaken blue light entering human eyes. Blue light is mainly produced by mobile phones and computers in life. The blue light on the electronic screen is unchanged, so a film can only be designed on the lens to absorb blue light. This can effectively reduce blue light. The complementary color of blue light is yellow, so the yellowing of the anti-blue lens is normal. The material of an anti-blue light lens can effectively shield the blue light. If the blue light is removed from the white light we usually see, it will show yellow, which is a normal phenomenon.
Why should the surface of the lens be hardened?
Compared with glass lens, resin lens has the characteristics of lightness, safety, and comfort, but resin lens friction with dust or gravel in the process of use, resulting in lens wear and forming scratches. These scratches in the center of the lens can interfere with vision.
Therefore, in order to improve the wear resistance of resin lenses, it is necessary to add a layer of anti-wear film to the surface of the lenses. This is the hard coating technology of the lenses, which is called Hard coating.
How Do Bifocal Glasses Work?
After learning some basic information about bifocal lenses, you should know how the bifocal glasses work.
With a pair of bifocal glasses, it would be convenient since they combine all your vision needs into a pair of glasses and you do not need to switch two pairs of glasses frequently. Bifocal glasses are usually designed to for those people who are over the age of 40-45 that need additional help with their near vision due to the effects of presbyopia where the crystalline lens inside the eye naturally begins to lose its ability to focus on near objects.
If you work in the office, you may need a pair of bifocal glasses. The top distance vision in the top of the lens can be used for meetings or presentations and the near vision in the bottom of the lens can be used to look at the computer screen or at documents.
