Acquisition of optometric degrees when buying glasses online
The degrees are mainly got from three places: physical store paid optometry data, hospital optometry data, previous degree (remember or retest). If you are in the hospital for optometry, it should be noted that there must be test glasses to try on, if there are no test glasses to try on, the data is not accurate.
There are three processes for resin-changing lenses.
The incorporation method, known as bulk polymerization, is similar to the method of glass lens, that is, one or more photochromic dyes are directly incorporated into the polymer monomer of the substrate for bulk polymerization, and the lens formed after curing will change color. Discoloration dye is completely integrated into the resin lens substrate, so the lens made of color persistence is very good.
The uniformity of discoloration and the depth of color after discoloration are highly related to the thickness of the lens. Because the thickness of the lenses at all levels is different, there will be a color difference between the depth of discoloration and the uniformity, and the uneven phenomenon of high brightness is more obvious.
The film type is known as the coating method. It is the chromatic resin lens by coating or dipping in a layer of chromatic dye on the base of the resin lens. Because the coating covers the surface of the lens, the color uniformity is good. The coating, which is only about 0.05mm thick, does not provide enough molecules to make the lens dark enough, so the color is relatively less dark, and the discoloration lasts slightly longer.
Infiltration, known as the penetration method, is to use the principle of penetration, through the thermal diffusion method to make the color dye permeate the surface of the resin lens sheet material, with diffusion depth up to 0.15~0.20mm. The lens has a constant color change characteristic. There will be no inconsistency between the center and the surrounding color as the luminosity gets darker. The color-changing resin lens made by infiltration type has the benefits of uniform color-changing, small color difference, fast and thorough color-fading, which is the mainstream of color-changing technology at present.
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, varifocal glasses have no specific area of lens strength, but progressive lens zones.
Varifocal glasses have three different prescriptions in one pair of glasses, allowing you to correct near and far vision. And it is convenient for you since you don’t have to change the glasses frequently.
Anti Fog Safety Glasses Safety Goggles Over Glasses
Anti-fogging safety glasses reduce deformation, effectively prevent fogging, and avoid fogging which affects vision in use. The angle of the goggles can be adjusted in accordance with the different foreheads (30 degrees). They can use a variety of large-size myopia goggles, safety glasses. It can effectively protect eyes from saliva, sand, metal fragments, and so on.
The mission of Harmony Eyecare is to create an unforgettable eye care experience for every patient by providing unmatched customer service, comprehensive patient education, and superior product quality. Providing the highest quality lenses and craftsmanship, their state-of-the-art, the professional lab provides the latest lens technology and generous warranties. There are plenty of options with price designer frames to fit every budget.
What is a progressive lens?
Progressive multifocal lenses are lenses with different upper and lower powers for seeing far above and below for seeing near. The distance from the fixed far power above the lens to the near power fixed below the lens does not change suddenly, but a gradual transition between the two through the gradual change in refractive power. Compared with ordinary lenses, there are many advantages. The appearance of the lens is like a single vision lens, and the dividing line of the power change is not visible. Not only is the appearance beautiful, but more importantly, it protects the age privacy of the wearer, and there is no need to worry about revealing the age secret due to wearing glasses.
Since the change of the lens power is gradual, there will be no image jump. It is comfortable to wear and easy to adapt. So it is easy to be accepted. Because the degree is gradual, the replacement of the adjustment effect is gradually increased according to the shortening of the short distance. There is no adjustment fluctuation, and it is not easy to cause visual fatigue. Clear vision can be obtained at all distances in the visual range.
Such a pair of glasses meets the use of long-distance, near-use and various distances in the middle at the same time. It is especially good news for teachers, doctors, music workers, and computer operators, because these people not only need to see far and near objects clearly, but most of the time they also need to be able to see middle distance objects such as blackboards, piano scores, and computer screens. . This is not possible with any lens other than progressive lenses.
What Are Anti-Glare Glasses?
Anti-glare glasses are made with lenses that have an anti-glare coating or anti-reflective coating. This is an extremely thin layer placed on the lens itself so as to remove any reflections you might see from the surface of the glasses. This improves your vision by reducing the amount of glare that reflects off of your lenses.