Progressive lenses and single vision lenses
An optical lens that has only one luminosity on a single vision lens and does not have special functions.
The curvature of the front surface of the progressive lens increases continuously from top to bottom, and the refractive power increases gradually and continuously from the distance zone located on the upper part of the lens until the near zone at the bottom of the lens reaches the required near-use refractive power. A pair of glasses can be used. You can see far away, you can see close, and you can see objects in the middle distance.
Can you buy a pair of rimless glasses with a high prescription?
Rimless glasses have many benefits. Rimless glasses are a popular choice for eyewear wearers in terms of performance, price, and styling. However, you may wonder if rimless glasses will fit your prescription. The answer is yes, you can get rimless glasses, even with a prescription.
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.
Advantages of Plastic Frames
Plastic frame material is mainly various types of plastic polymer materials. With the characteristics of impact resistance, suitable for athletes to wear. The plastic used to make the frames can usually soften under the condition of the heating, and some plastic frames can be fine-tuned without heating. The plastic frames are not allergic and lightweight, making them suitable for children and people of all ages. And because the color is rich, and there are many styles. They become the choice of fashionable sunglasses. Plastic frame cost is low, and the process is simple. Because of its lightweight, plastic glasses frame is not easy to allergy. Because of its color and material characteristics, they become the fashion personage sunglasses or decoration choice.
What is the cheapest way to buy prescription glasses?
The choice of frames is not only good-looking but also has a lot to do with whether the polished glasses can be worn correctly. Therefore, special attention should be paid to the selection of spectacle frames, and the pupil distance and the optical center of the spectacle lens should be placed in a suitable position. It should also match the shape of the face so that the paired glasses are not only beautiful but also comfortable to wear. If you don’t choose a frame according to this, but choose anyone according to the general rules, the pupils will not match the optical center of the glasses, and the deflection center of the glasses will appear, causing the prism effect, which is very harmful to the eyes. How do choose a frame? Glasses are worn on the face after all, and they have a decorative effect, so you still have to see if they fit your face shape. In addition, the weight should be light and the frame size should be appropriate. It is best to measure the interpupillary distance, otherwise, it is easy to cause squint and cross-sight. It is safer for children to choose a plate frame with resin lenses. There is a wide range of options for adults. Glass lenses have higher hardness and are not easy to wear, while resin lenses have lower hardness but lightweight, good clarity, and higher protection against ultraviolet rays. Although crystals are expensive, they have high ultraviolet and infrared transmittance.
Diamond-shaped face with irregular glasses
A diamond-shaped face is more difficult to choose frames because facial features are more distinctive. When choosing glasses, you should also choose more distinctive ones to modify your face. Irregular glasses, such as hexagonal or pentagonal glasses frames, can be selected. The fashion sense is particularly strong. It looks like a little girl's vision and has a good modification effect.
Different Type of Lenses: How to Choose
In this section, we will list some of the lenses for glasses.
Plastic lenses: In 1947, the Armorlite Lens Company in California introduced the first lightweight plastic lenses. The lenses were made of a plastic polymer called CR-39, because it was the 39th formulation of a thermal-cured plastic developed by PPG Industries in the early 1940s. Plastic lenses are light and low cost.
Polycarbonate lenses: polycarbonate lenses were first introduced in the 1970s and they have become increasingly popular anad remained for a long time. Polycarbonate glasses are slighter and significantly more impact-resistant than CR-39 plastic, making them a preferred material for children’s eyewear, safety glasses, and sports eyewear.
