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.
What Are Bifocals?
There are several kinds of lenses available in the market. Now, there is a kind of lenses by stacking two different kinds of lenses together and they are called a bifocal lens. Bifocal lenses are lenses with lines separating two different prescriptions. There is a presence of a distance lens at the top and the lower part has a lens that can be used to view the objects placed nearby.
Bifocal lenses are designed for people who have presbyopia, a condition in which the person can’t see the nearby placed objects. Presbyopia is an age-related condition, often occurred when people are over 40 and people often have blurred vision.
At the same time, there are different types of bifocal lenses present and they provide the same user which is the lower part of the lens is used to view the nearby objects or to do work related to reading and writing while the upper part of the lens is used to view the objects placed at a faraway distance or to do an activity like driving.
So, in the following section, we will show you the different types of bifocal lenses.
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.
How to Choose Glasses for Long Face?
Bold shapes and eyeglasses with decorative details are also a smart choice since they help draw attention to your eyes and can add width to your face. Be sure to avoid narrow or rectangular shapes, which can make your face appear longer.
Square glasses: if you have a long face, you can try square glasses whose sharper corners can help to balance out the length of your face and complement your narrow features. Choose frames that are slightly wider than your cheekbones to make your face appear broader.
Two-toned glasses: if you have a long face shape, the two-toned glasses would be a good choice. The color-top frames create an optical illusion that draws focus upward toward your eyes rather than to the length of your face.
The inadequacies of bifocals
The field of vision is smaller than that of the single vision lens, especially for the close view. For example, reading and reading newspapers need to make it coordinated with the head movement, there are optical defects of image jump and image displacement. There is a boundary, and it is easy to be seen that wearing a bifocal lens exposes age. Bifocals clearly demarcate the near and far regions, affecting appearance and vision. And when far view and close view change, the objects will jump. Because most myopic patients have a lag in the adjustment response, wearing bifocal lenses not only does not delay the development of myopia but has side effects. Therefore, bifocals are not suitable for teenagers to control myopia, and only a few special patients need to wear bifocals.
How much do a pure titanium eyeglass frame cost?
For the plastic frame, without a fixed metal rod in the middle, the retail price of the exclusive store is 30 dollars or so. Resin-coated metal frames are inexpensive, 35 to 85 dollars in the store. Because pure titanium is more difficult to make, and the material is more expensive, the frame price often starts from 50 dollars. For example, the ordinary Seiko pure titanium eyeglass frame is about 85 dollars. In Europe and the United States and other developed countries, titanium spectacle frames are popular as a kind of high-grade decoration and fashion. In the past two years, the domestic began to be popular little by little. Titanium spectacle frame belongs to high-grade consumer goods, and the price is usually above 50 dollars.
Price positioning
In terms of positioning, it should conform to students' purchasing behavior, that is, the middle and low-grade products are mainly used, and the appearance requirements are stylish and novel. In addition, you can be properly supplemented with a small number of high-end products, because your market is not only the school but many residents around.
