Data obtained by computer optometry alone may not be accurate.
The first thing is to go to the optometry store, or the hospital to do a glasses degree test, namely to get single optometry. The precision computer optometry has errors, and computer optometry is only used to measure separately monocular degrees. What we need is the best visual effect of the binocular match, so the exact prescription needs to be carefully confirmed by comprehensive optometry. Optometrists will ask everyone to try on the insert lenses again, and even need to repeatedly try on several degrees of lenses, in order to finally determine which degree is the most appropriate, because even the professional optometry data is only a rough range, only based on the data of glasses is not necessarily suitable for their own. You can use a focometer to measure the actual parameters of the glasses you are wearing. If you are still unsure of your prescription, it is recommended to fax, mail, or mail your prescription to the merchant when placing your order.
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.
How Do Pinhole Glasses Work?
Compared to traditional glasses, pinhole glasses work differently. Traditional glasses correct your vision often by collecting rays of light as they enter the eye and forcing them to converge on the retina rather than behind or in front of it.
However, pinhole glasses limit the amount of light entering your eyes so as to enable people to see more clearly.
New Fashion Police Men's Polarized Sunglasses Driving Glasses
They have high quality. The lens material is a polarized lens. The frame color is silver/gold/brown/black and the visibility rate is 99(%). UV protection rating is UV400,with 100% UV protection. They are suitable for driving, fishing, daily leisure.
Most accidents happen at night and before dawn, which has a lot to do with glare and the problem of many people having blurred vision in the dark. Every driver knows the trouble of driving at night: glare, bright reflections, and bright lights from oncoming traffic. In addition, poor visibility at night can make driving tiring and dangerous!
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.
The function of eyeglasses cloth
Under a powerful microscope, the fibers of the cloth are more closely arranged than those of ordinary cloth, and the material itself is softer than ordinary cloth. That's because eyeglasses under the eye are almost always coated, with each standard lens having seven layers of different functions on the front and back surfaces, to extend lens life. It can thoroughly remove the stubborn stains left on the lens to make the picture clear. It can clean all kinds of glass, resin, and other materials of glasses, glass mirrors, and other mirror surfaces, remove stains, and grease absorption.
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.
