Refractive index of spectacle lens
It is generally believed that the higher the refractive index, the better the spectacle lens. Such spectacle lenses are relatively thin, and of course, the price is a bit expensive. When the refractive index increases, the direction of the light entering the lens will change greatly, the focus will move to the lens, the focal length will be smaller, and the diopter will become larger. In order to keep the diopter unchanged, it is necessary to reduce the curvature of the lens, that is, to reduce the curvature of the mirror surface, so that the thickness of the lens can be reduced. This is why the larger the refractive index, the thinner the lens is. Under the same premise of other things, the larger the refractive index, the thinner the lens, the lighter and more beautiful the lens, and the higher the price, but the larger the refractive index is not the better.
Semi-rimless glasses
With a half-frame design, the retro round glasses can be paired with a very thin metal frame, indicating the literary and elegant temperament. The frame with only the upper part of the lenses circle covering the lens integrates lightness and steadiness, highlighting the sense of fashion, not only shows the wisdom of business elites but the natural and free affinity. They are not heavy and relatively firm. It is suitable for different kinds of occasions. It can be used for business occasions, leisure occasions, and parties. It is stylish and composed, reflecting the quality of life.
The birth of progressive lenses
In 1907, British optometrist Owen Aves first proposed the concept of progressive lenses and got the first patent of progressive lenses. In 1910, Henry Orford Gowlland designed and made a similar lens in Canada, but technical limitations prevented it from succeeding. In 1959, Bernard Maitenaz, a French optical and mechanical engineer, developed the first progressive lens, which was successfully put into the commercial market for the first time and became a milestone in the history of world optometry. With the development of science and technology, the design of progressive lenses has been greatly developed.
Seek adjustment in stores
It occurs redness and pain in the ear area. It could be that the structure of the glasses and position doesn't suit your face shape. When you're in an optician's shop, ask an optician for help in adjusting your glasses or changing the frames. Think about if the frames fit or are a little heavy. Suggest you can change to another pair. You should try a suitable and not heavy frame. You go back to the eyewear store and ask a professional to shape your frame in accordance with the outline of your ears again carefully. If you feel a little uncomfortable when you try it on, adjust it.
What is the cheapest way to buy prescription glasses?
Every time I wear new glasses, I always feel dizzy when I first put them on. Although the store always says this is normal, the glasses must be comfortable to wear, and there should be no obvious dizziness or visual distortion after wearing them. We can’t make our eyes fit the glasses, we must make the glasses fit our eyes.
Buy Glasses For Kids - Appropriate Frame
To choose a frame for the child, we must first consider the measurement of the bridge of the nose of the child, and the pupil distance. Furthermore, if the eye is farsighted and the pupil distance is too large, it will produce the prism effect from the bottom out. If it is myopia and the pupil distance is too large, it will produce the prism effect bottom-inward. If the pupil distance is too small, it will have the opposite effect. The frame should be light, light glasses will not affect the development and shape of the child's nose bone.
How to Choose Glasses for Long Face?
Bold shapes and eyeglasses with decorative details are also a smart choice since they help draw attention to your eyes and can add width to your face. Be sure to avoid narrow or rectangular shapes, which can make your face appear longer.
Square glasses: if you have a long face, you can try square glasses whose sharper corners can help to balance out the length of your face and complement your narrow features. Choose frames that are slightly wider than your cheekbones to make your face appear broader.
Two-toned glasses: if you have a long face shape, the two-toned glasses would be a good choice. The color-top frames create an optical illusion that draws focus upward toward your eyes rather than to the length of your face.
