What are bendable glasses called?
Bendable frames, or memory metal frames, are metal frames that can be twisted, bent, and shattered without breaking or losing their original shape. It's made of a kind of smart metal that has a memory. Its microstructure has two relatively stable states. At high temperatures, the alloy can be changed into any shape you want. Memory metals are mainly nickel-titanium alloy and other materials. The structure of these alloys varies with temperature in the solid-state, the shapes of these alloys can be changed as needed, and will automatically return to their original shape at a given temperature. One unique aspect is its ability to return to its original shape, although the frame has been twisted, bent, or crushed. They are lighter and more durable than traditional metal frames. The bendable frames are made of composite metal alloys for bending properties. These lenses can be twisted and bent, and when they are released, they return to their original shape.
What Are Progressive Lenses?
Progressive lenses have grown in popularity and are one of the most common solutions to treat vision loss that occurs with age or presbyopia. This eye condition occurs when the eye loses some of its flexibility and ability to adjust to clear seeing objects at different distances. Presbyopia often occurs among adults who are over age 40 and is very easy to correct with a proper and prompt diagnosis.
Progressive lenses are often used to correct this eye condition. Progressive lenses are a modern alternative to bifocal glasses, which provides two prescriptions in a single set of glasses. Bifocal glasses are a better solution than carrying around multiple pairs of glasses. Progressive lenses were developed to resolve some of those common issues and to provide better aesthetics. Progressive lenses provide a smooth transition and can accommodate up to three prescriptions and are a replacement for both bifocals and trifocals.
Why Do My Glasses Give Me a Headache?
Why do my glasses give me a headache? There are a lot of reasons for new glasses headaches. So, in this section, we will list some of them.
Muscle strain: each eye contains six muscles. Since your eyes learn how to view the world through a new prescription, these muscles have to work harder do differently than they did before. So, this action may cause muscle strain within the eye and a headache. If you are wearing glasses for the first time or if your prescription has changed significantly, you may be prone to this effect.
Multiple lens power: if you have changed to a multiple lens power of glasses like bifocal glasses, varifocal glasses, it may be difficult to adapt in a short time. So, this change will lead to some problems such as headaches.
Poorly fitted frames: as for the issue of new glasses headaches, if you glasses fit too snugly across your nose or cause pressure behind your ears, you may get a headache. So, when purchasing a new pair of glasses, selecting a fitted one is important.
Wrong prescription: why do my glasses give me a headache? It can be caused by the wrong prescription. If your eyeglasses prescription is too weak or too strong, your eyes will become strained causing headaches. So, if you still suffer from headaches after wearing the new glasses for a few days, contact your eye doctor and check the prescription again.
What is hard coating on lenses?
Lenses are mainly added in two kinds of film: anti-reflection film and hard film (and some manufacturers produce anti-fogging film and mirror film, but not common). The anti-reflective film is mainly by coating the front surface of the lens with multiple layers of transparent materials with different refractive index and thickness to reduce the excess reflected light on the surface of the lens, by using the principle of light interference. The film can be applied to both glass and resin lenses. The way of hard film plating is usually a soaking process. After many times of soaking and cleaning, soaking in an organic solution containing ultrafine silicon element for a certain time, and then keeping it at a certain temperature for 4-5 hours, the fixed polymerization process of the film has been completed. The surface wear resistance of CR-39 coating can be increased by 2-4 pH, which is similar to the hardness of optical glass lenses.
Choose clear glasses with the right materials for kids.
A critical point for children to choose frames is to think about the weight, to avoid wearing for a long time, or they will be uncomfortable, unstable, easy to slip. It is recommended to choose an ultra-light plate or TR90 lens frame, which has good chemical properties, good thermal stability, with no deformation, good recovery, and no side effects, lightweight, and convenient material.
Do all glasses come with nose pads?
The glasses without the nose brace are plate glasses. In reality, there is still a nose pad, but it is relatively small and it's part of the frame. The westerners have high nose bridges, and many glasses have no or very small nose pads. For example, Harry Potter's glasses have no nose pads. European and American brands will change their nose pads for the Asian market. Eyeglasses without a nose pad rely on the bridge of the nose to support the center beam. It's hard for Asians to stand up, and their eyes are more protruding than sunken like westerners. Glasses are usually demanded to keep a 12mm distance between the lens and the eyeball, otherwise, the optical performance will have a great impact.
Polycarbonate vs Plastic Lenses: Which One Is Better?
From the above information, you may have learned some features of polycarbonate glasses and plastic lenses. So, do you know which one is better?
Here are some a few differences between both lenses to determine which one is better.
- Polycarbonate lenses are more expensive than plastic glasses.
- Polycarbonate lenses are very resistant to tint compared with plastic lenses which accept tints.
- Polycarbonate glasses have inherent UV protection, while plastic lenses do not have.
- Polycarbonate glasses have higher impact resistance and offer greater protection than plastic lenses.
- Polycarbonate glasses are lighter than plastic glasses.
- Plastic glasses have a higher optical clarity than polycarbonate lenses.
So, from the above part, you may have learned which one is better and you may have a decision of how to choose.