It is probably the oldest online reading glasses store on the Internet. It offers the best optical quality reading glasses, computer glasses, prescription glasses frames, bifocals, sunglasses, foldable glasses, magnifying glasses, and eyewear accessories. A complete range of accessories is sold, including glasses cases, glasses holders, chains, magnifying glasses, lens cleaners, and cleaning cloths. Zero-power computer glasses are provided for the younger generation. These frames can be customized to your optician's prescription.
What Are Transition Lenses?
Transition lenses, also called photochromic glasses are eyeglasses lenses that change their colors with light. The transition lenses darken in the sunlight and lighten in the softer light or the dark. These transition lenses provide the convenience of sunglasses without having to wear them over your prescription glasses and having to constantly switch between the two.
But there are some common transition lenses problems. So, we will list some of them. Are transition lenses worth it? After reading this post, you will find them.
How Do Progressive Lenses Work?
So, how do progressive glasses work? Progressive lenses allow you to see at all distances with one pair of glasses. They start with your distance prescriptions at the top of the lens and increase as you move toward the bottom of the lens. You can move your head position to allow you to focus through different areas of the lens.
Move your head upwards to see something in the distance, and hold it straight for intermediate or arm’s length vision and down for near vision for objects that are close up. Apart from the aesthetic improvement of the lens without the line segments, progressive lenses avoid the visual discontinuity or image-jump when your eyes shift from one zone to the other in non-progressive multifocals.
How to buy contact lenses online?
Choose the right contact lens for your situation. Base arc and degree need to be added in the hospital or optician shop to determine. Try not to buy according to the framed degree. Some businesses claim to have the lenses having South Korea's silicone hydrogel, with annual throwing. They are not to be believed, because the material characteristics of the silicon hydrogel are not capable of making long-time discarded type lenses. There are a lot of things to pay attention to in order to properly wear contact lenses. For example, a medical optometry sheet is the premise of attention. Each pair of contact lenses is marked on the package of the basic arc, diameter, water content, diopter, and other parameters. Only according to the optometry sheet, you can choose the correct basic arc, diameter, and diopter. At the same time, there is a certain distance between the glasses and the cornea.
How long do plastic frames last?
Plastic frames are made of non-biodegradable materials and are possible to last forever. If the frame is made of acetate, the layers of acetate fibers make the frame vary in degrees of transparency and pattern. The plastic frame manufacturing process makes the plastic frame more brittle than the acetate frame. In this sense, the acetate frame has a longer service life. Then the plastic, which is made of SAP, will never break down. Depending on the circumstances, it could take years. If the lenses are polycarbonate, the material takes hundreds of years to break down naturally. If TR-90 is normally stored, not exposed to the sun, and put in the box with cloth wrapped, and then you can keep 3 years, there is no effect.
Design principle of progressive multifocal lens
For the same piece of the lens, the top is used to see far, the bottom is used to see close. The upper and lower degrees are different.
There is not a sudden change in the distance degree fixed above the lens to the near degree fixed below the lens, but a gradual transition between the two through gradual changes in refractive power, which has special benefits over common bifocals or trifocal lenses.
The Disadvantages of Trivex Lenses
In this section, we will show you the disadvantages of Trivex lenses.
- Trivex lenses have less availability, especially compared with polycarbonate lenses.
- Trivex lenses cannot provide the same degree of thinness as high-index lenses.
- Trivex lenses are expensive than regular lens materials.