what does non prescription glasses mean? | KOALAEYE OPTICAL

what does non prescription glasses mean?

Does it take time to adjust to progressive lenses?

How long should it take to get used to progressive lenses? I have never worn glasses before.Progressive lenses were developed to allow easy switching between near and far views. Progressive glasses are divided into four parts. The upper part is the far-light region. The lower part is the near-light region, and the middle part is a variable light region. From top to bottom, if the hyperopia film is gradually increased and the myopia film is gradually decreased. The middle variable area is on both sides of the astigmatism area. Because of the prism effect, when you see things, through this area, the object will be blurred, and the eyes will feel uncomfortable. If the height of the frame itself is very small, the transition zone of progressive multi-focus is very narrow, and the eyes may not adapt to the sunglasses. The current design of progressive lenses is still not mature. Imported brands are relatively stable but expensive, and domestic brands are not mature in design. For various reasons, progressive glasses may be difficult to adapt to wearing.


What Are High-Index Lenses?

High index lenses are eyeglasses lenses that are designed to be thinner and lighter than regular lenses. High-index lenses have a high refractive index than their conventional counterparts. So, they are generally recommended for people who have significantly high refractive errors and strong prescriptions for nearsightedness, farsightedness or astigmatism.

High-index lenses correct all types of refractive errors. And they are also available as single vision lenses, or a reading prescription that corrects presbyopia, such as in a bifocal or progressive lens.

High-index lens has a higher refractive index and which is ranging from 1.53 to 1.74. A lens with an index of 1.74 could be up to 50 percent thinner than a regular plastic lens with an index of 1.50.



Leimi Driving Glasses

With professional production and sales of sunglasses/flat glasses/sunglasses, Leimi has been focusing on the fashion aesthetics of sculpted glasses. They are presented through the exquisite selection of materials and fashionable and comfortable design. Leimi carefully makes glasses and discovers the beauty of the world together. Leimi advocates for consumers to experience the number of products through the exquisite materials and fashionable and comfortable design of various glasses products. Leimi believes that it can impress consumers with its products. Since its establishment, Leimi has always been striving to treat customers with high-quality products and good service. At present, Leimi's main products are swimming goggles, reading glasses, sunglasses, lenses, anti-radiation glasses, sunglasses for women, children's glasses, glasses frames, polaroid glasses, driver's glasses.


Glasses Size - Lens Width

Lens width is the width of a lens, measured in millimeters, from one side of a lens to the other side of that lens. This is the most important measurement to make sure the frame fits your eyes.



Why should the surface of the lens be hardened?

Compared with glass lens, resin lens has the characteristics of lightness, safety, and comfort, but resin lens friction with dust or gravel in the process of use, resulting in lens wear and forming scratches. These scratches in the center of the lens can interfere with vision.

Therefore, in order to improve the wear resistance of resin lenses, it is necessary to add a layer of anti-wear film to the surface of the lenses. This is the hard coating technology of the lenses, which is called Hard coating.


Gainesville Opticians

Each frame is an extension of your personality. Use your favorite frame to give you the ideal vision. There are a variety of lenses that fit any prescription, including progressive ones. Gainesville Opticians provides a customized collection of frames and styles from brands we know, trust, and love.


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Parameters of lens material selection

Abbe number

Since the refractive index of the lens material varies for the light of different wavelengths, and white light is made up of various colors of light of different wavelengths, the dispersion phenomenon occurs when the lens refracts white light. The dispersion coefficient is an important index to identify the sharpness of lens imaging, which is usually indicated by Abbe number (Abbe number = dispersion coefficient). The larger the Abbe number, the smaller the dispersion, and vice versa, the smaller the Abbe number, the larger the dispersion, and the worse the resolution of the image.

Impact resistance

Humans have been using glass lenses for about 300 years, and it was not until 1947 that the first resin lenses made of CR39 were produced. A big reason for using resin lenses is their safety, i.e. impact resistance. Only lenses that pass the Drop Ball Test are considered safe. Combining the above two parameters, we can compare different lenses.

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