What Are Varifocal Glasses?
Varifocal glasses, also known as varifocals, varifocal lenses, or progressive lenses, have a gradual change in strength from the top of the lens to the bottom with multiple focal points in between. Unlike bifocals, varifocals glasses have no specific area of lens strength, but progressive lens zones.
As mentioned above, varifocal glasses have three different prescriptions in one pair of glasses, allowing you to correct near and far vision. So, they bring you great convenience since you don’t need to change the glasses frequently.
However, there are also some common problems with varifocal glasses and we will show you the disadvantages of varifocal glasses.
So, in the following section, we will show you the disadvantages of varifocal glasses.
How many degrees of myopia do I need to wear glasses?
Students are the most nearsighted because they need to read and study every day. Many people have myopia during their student days. During the physical examination, everyone will check their eyesight first. Generally speaking, if the visual acuity is lower than 0.6, it means that you may be near-sighted to 0 degrees. At this time, you need to go for optometry to see the specific vision situation and see if you need to wear glasses. If the visual acuity tested exceeds 200 degrees, you must wear glasses at this time. If you do not wear glasses, your vision will be greatly affected, and the degree of myopia will rise quickly. For this reason, you must wear glasses in time to correct your vision. If the degree of myopia does not exceed 0 degrees, this is pseudo-myopia and does not require glasses. However, you should always take care to protect your eyes, avoid staring at things at close range for a long time, and don't let your eyes get too tired, so your vision will slowly return to normal.
Common Problems with Varifocal Glasses
In this section, we will list some common problems with varifocal glasses. The most common problem with varifocal glasses is people being unable to focus on what they need to. Losing focus often leads to some discomforts such as headaches or dizziness when performing tasks that require quick changes in near and middle-distance focus.
Besides, some people also experience a sort of swimming feeling when they are walking. It may be caused by being very aware of the distortions in your peripheral vision as well as the reading portion at the lower part of the lenses.
So, how to use varifocal glasses? The best way is to keep yourself from looking downward as you walk. You may also experience soft focus at the edges of the lenses and need to move your head more to see near objects better.
Is titanium alloy necessarily worse than pure titanium?
In the common case, the introduction of a titanium frame will have a detailed material label, what titanium and what material is it made of, such as titanium nickel alloy, titanium aluminum vanadium alloy, and so on.
The composition of titanium alloy determines the quality and price of the frames.A good titanium frame is not necessarily worse or cheaper than pure titanium.It is difficult to ensure the quality of titanium alloy which is very cheap in the retail market.In addition, titanium alloy is not to reduce the cost, but to improve the performance of the material.Usually, the memory frame on the market is made of titanium alloy.
The function of eyeglasses cloth
Under a powerful microscope, the fibers of the cloth are more closely arranged than those of ordinary cloth, and the material itself is softer than ordinary cloth. That's because eyeglasses under the eye are almost always coated, with each standard lens having seven layers of different functions on the front and back surfaces, to extend lens life. It can thoroughly remove the stubborn stains left on the lens to make the picture clear. It can clean all kinds of glass, resin, and other materials of glasses, glass mirrors, and other mirror surfaces, remove stains, and grease absorption.
Metal frames have many benefits.
It has a certain hardness, good softness, good elasticity, wear resistance, corrosion resistance, gloss, and good color and luster.?For example, for the high nickel alloy frame, nickel content reaches more than 80%. It mainly has nickel-chromium alloy, manganese nickel alloy. High nickel alloy’s corrosion resistance is better. In addition, the material elasticity is good.?Titanium frame has a high melting point, light material, strong corrosion resistance, and solid electroplating. The eyeglass frame that uses pure titanium is deft and comfortable, more in accord with human body engineering. And flexibility is good, long-term use is not out of shape. And they do not fade, do not cause skin allergy, relatively durable.? Memory titanium alloy frame refers to a new alloy made up of nickel and titanium according to the atomic ratio of 1:1.?Memory titanium is more resistant to corrosion than high nickel alloys but less resistant than pure titanium and β-titanium.
Why Are My Progressive Lenses Blurry?
Progressive lenses are optical lenses designed for simultaneous correction of far, medium and near. Progressive lenses use polishing technology to achieve a gradual transition between the two focal lengths. With progressive lenses, people do not have to switch their glasses for different purposes.
However, with the usage of progressive lenses, there are some problems of progressive voices. One of the most commonly reported side effects of progressive lenses is blurry or fuzzy peripheral vision. The blurriness is usually most noticeable through the lower portion of the lens and to the left and right of near and immediate zones.
