What is the best lens material?
Crown glass was first used to make lenses. The glass melt was blown into a crown, or hollow sphere, and then reheated in the center of a rapidly rotating plate, which was then unrolled and flattened by centrifugal force. Flat and thin edges are cut into suitable shapes to make window panes. The circular bulge in the middle is the prototype of the lens. The glass material used to make lenses was originally colorless transparent glass with a refractive index of 1.523. Other substances were added to the lens to improve its ability to absorb ultraviolet light.
Why is a prescription for glasses different from a prescription for contact lenses?
The frame glasses degrees are the optometric degrees of the eye, and the difference between the frame glasses degrees and the contact lens degrees is mainly due to the different contact distances between the two lenses and the eye. Usually, degrees of contact lenses and glasses need to be converted by a professional through vertex diopter. The conversion formula is Fc=Fs/(1-d×Fs). In the formula, Fc is the diopter of contact lens, Fs is the diopter of glasses frame lens, and D is the distance between frame glasses lens and cornea. Assuming that the prescription of frame glasses is -4.00d and the distance between lens apex is 12mm, the prescription of contact lenses is -4.00/ [1-0.012×(-4.00)] = -3.82d.
Why do you need to adjust your glasses?
After wearing glasses for a period of time, the frames will become deformed and loose. Due to the deformation of the frame, the wearer may experience blurred vision, dizziness, visual fatigue, and other symptoms, the glasses need to be adjusted regularly. And because the shape of each person's face and the relative position of nose and ears are different, you need to adjust your glasses according to your own features. To make wearing comfortable, glasses do not overpress the nose and ears. After wearing glasses, it is advisable to have no tenderness at the contact point and not to slide down the head frame. The frames have to be made fundamental adjustments after assembly to meet fundamental standards.
Is it cheaper to buy glasses online？
Online glasses matching adopts the operation mode of online platform and factory-style centralized mirror matching center, and returns all the huge site, labor, and intermediate costs saved in physical stores to consumers, providing better glasses matching the quality and lower product price! So, the price is cheaper.
Free home trial
They know how important it is to try and touch glasses before buying them. That's why Free home trials are available at Glasses Direct. And it's totally free! They are delivered daily to your home, so every customer gets an unlimited number of home trials, covering hundreds of unique styles, and it's an unmatched experience. At Glasses Direct, they make it easier to help you find your next pair of glasses.
Why do glasses with the same prescription feel different?
The style of the frame has changed. The structure of the new glasses and the old glasses (half-frame, rimless, full-frame) may be different, and the angle of the glasses may also be different, which will cause visual differences and the symptoms of dizziness after wearing the new glasses. If you used to wear rimless glasses or half-rim glasses before and switch to full-frame glasses, you will feel that his field of view is limited and you will feel a little uncomfortable when you see the edge of the frame. If you wear full-frame glasses before, you will feel the edge of the lens when you change to half-rim glasses. It's too bright to adapt. There is another situation, changing from a frame with a nose pad to a frame without nose pads. Because the distance between the lens and the eye has changed, the position of the nose pad has also changed, which directly affects the relative position of the optical center and the pupil, as well as the distance from the back vertex of the lens to the cornea, which naturally affects the visual difference. In this case, you can fine-tune the nose pads, or after a short-term adaptation, you can generally return to normal.
Normally, opticians do not want to change their original visual habits (to maintain visual continuity) and want to copy a pair of glasses with the same vision. When optometry, they must provide the used old glasses and their optometry record sheet for inspection. With personnel reference. Simply put, comfort is equal to habit. If you want new glasses to wear comfortably, you must keep your original habits. It's not just the reproduction of luminosity. If you don't wear suitable glasses often, you will feel uncomfortable once you wear them.
American Eyewear Brand - Sola International
Sola is a global leader in the design and material development of eyewear lenses. Through intensive investment in research and development, Sola continuously creates innovative new products that give people around the world a better perspective on all aspects of their lives. Sola is mainly engaged in the design, development, production, and sales of different progressive high-value-added optical products. Its main products are optical lenses, sunglasses, safety lenses, and optical instruments. They have manufacturing facilities in the United States, Australia, Ireland, France, Brazil, Venezuela, Mexico, Singapore, and China. And have 41 distribution centers in 17 countries. Every day, customers in more than 50 countries and regions choose from more than 20,000 high-quality products provided by these distribution centers.