Cellulose Acetate
Acetate is a kind of thermoplastic resin obtained by esterifying acetic acid to acetic anhydride under the action of a catalyst. Acetate is resistant to water, gasoline, mineral oil, and lipids, weak alkaline solutions, and acids, excellent weather resistance, not resistant to ethanol, strong acids, and strong alkaline solutions. During thermoforming, it is very necessary to dry the material before forming. Acetate was born in the early 20th century, and was successfully trial-produced and industrialized by the UK in the early 1920s. At present, it is the second-largest variety in cellulose fiber after viscose fiber. Acetate can be used to make textiles, cigarette filters, film bases, and plastic products.
Oval frame
Soft and smooth lines, implicit and introverted, reflect the gentle and quiet fair maiden style. It seems that the first pair of glasses worn by everyone who is nearsighted is oval, basically in high school. It seems to have a student era of green implicit, quiet lady. Even in middle age, there are a lot of people who will choose a lot of beautiful styles of oval frames. It seems that in their hearts, they all want to stay young forever.
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The price is more favorable, and the function can be adjusted according to the strength of the sun's light. On sunny days, they can filter glare, protect the eyes from light stimulation. When they are worn on cloudy days, the lenses will lighten according to the light, preventing dimness of vision. ?And wearing comfort is also good. Traveling, climbing, driving, and so on can be used. ?As an emerging brand in recent years, the current user's popularity in the market is not small. In the design and functionality, they can meet the public, and at the same time, the cost performance is good.
What are optical frame glasses?
Optical glasses are transparent medium lenses. A pair of glasses usually consists of a lens, lens ring, nose pad, and temple, etc. The main materials are metal, plastic or resin, natural materials, etc. Through the refraction of the light, the central target can be clearly seen, thus playing a role in vision correction for the eyes with refractive abnormality.
Progressive lenses and single vision lenses
Single vision lenses are the most widely used optical lenses and are suitable for the general population.
Progressive lenses are suitable for below people.
① Myopia control lenses for teenagers. Progressive lenses are used to relieve visual fatigue and control the development speed of myopia.
② Anti-fatigue lenses for adults. Progressive lenses are used for teachers, doctors, people who use too much computer at close range to reduce visual fatigue caused by work.
③ Progressive lenses for Middle-aged and elderly people. A pair of glasses for middle-aged and elderly people to easily see near and far.
The hazards of rusty spectacle frames
The most common allergenic metal is nickel. Once allergy occurs, it can cause contact dermatitides such as redness, swelling, itching, and yellow water on the surrounding skin. Many alloy products in daily life contain nickel, such as coins, various alloy products, electroplated objects, spectacle frames, metal watchbands, belt buckles, artificial jewelry, underwear buckles, etc. Their direct contact with the skin will cause allergies to sensitive people. Therefore, the temples and nose pads are the parts that contact the skin with a larger area. In particular, the outer surface of the metal frame and the metal contain a large amount of nickel, which can cause rust spots and skin corrosion, and allergies through contact with the skin and the erosion of sweat.
Consider possible uncertainties after the lens is installed.
Usually, in-store frames are made of plastic samples rather than actual lenses, so they weigh slightly less. However, it is necessary to consider the approximate weight of the lens in advance according to its own degree when trying it on, in case the weight is not suitable for real wearing. If the pupil distance is too small, it is not suitable to wear a wider frame. The machinist should strictly follow the left and right pupil distance instead of taking the average, otherwise, there will be pupil distance error in the left and right eyes, which will cause discomfort in wearing.
