What Are Varifocal Glasses?
Varifocal glasses, also known as varifocals, varifocal lenses, PALs, or progressive lenses, have a gradual change in strength from the top of the lens to the bottom with multiple focal points in between. This allows you to see all distances and focus points through just one lens. Varifocal lenses are typically used when you have two prescriptions, one for distance and one for reading.
There are three regions of a varifocal lens which are distant zone, intermediate zone and, near/reading zone. Usually, the upper portion of the varifocal lens is the distant zone and the bottom portion of the varifocal lens is the near or reading zone.
One of the benefits of varifocal glasses is that you do not need to prepare 2 separate pairs of glasses or need to switch between frames for different vision needs.
Although glasses are the tool that corrects myopia, a lot of people like to dress up fashion with it now. Men's fashion frames allow you to express your taste and fashion sense and can increase your appearance and image. An eyeglass frame is an important part of a pair of glasses, mainly playing the role of supporting the lens. While the beautiful appearance of the eyeglass frame can play a certain role in aesthetics. Handsome frames add points for appearance.
Metal Eyeglasses
Whether you like classic looks or prefer rectangular and functional things, all metals will look new in 2021. Combining the trend of super large frames, you get a big round metal frame. These styles are not heavy and fit all face shapes, from round to square, and anything in between.
Optometry glasses are not professional
Some people will not only experience dizziness when they change their glasses but also have headaches, nausea, vomiting, inattention, neurasthenia, and other symptoms from time to time. And some people even deepen myopia. This is most likely due to unqualified glasses and inaccurate optometry. In short, this eye discomfort is caused by the inconsistency between the power of the glasses and the actual condition of the eyes. Optometry before filling a prescription is a very important step. In addition to checking myopia and astigmatism, it is also necessary to check for eye disease, binocular vision balance, monocular ability, primary vision discrimination, interpupillary distance, etc. In this way, suitable glasses can be fitted according to the overall situation of the person's eyes. The spectacles must also match the parameters of vertex, interpupillary distance, cylindrical lens axis position, etc. Otherwise, it will directly affect the effect of correcting vision, cause the user's visual fatigue, and increase the emphasis on power loss.
The benefits of bifocal glasses
People with myopia often need to wear bifocal glasses after the appearance of presbyopia. The upper and lower parts of the lens have different diopters. The upper part is used to see distant objects, and the lower part is used to read and do close work. In addition to presbyopia, some people who work long hours in close quarters need bifocals to reduce eye strain. Studies have shown that long-term nearsightedness is the main cause of myopia. According to the adjustment principle of the eyeball and the height of the patient diopter, a reasonable measure is to wear myopia glasses with full correction when seeing the blackboard in class. When reading and writing. they should take off glasses or wear low myopia glasses. But the practice of continuously removing and putting on or changing glasses is clearly unrealistic. Bifocal glasses will solve this problem.
Is there any relation between lens refractive index and lens definition?
First of all, in reality, from the point of view of the immediate situation, there seems to be no correlation. The refractive index is mainly related to the speed of light transmission into the lens. High refractive index lenses can be made thinner, lighter, and the technology required to do this is more sophisticated, so high refractive index lenses are more expensive. But does a high refractive index make the lens clearer? The higher the refractive index of the lens, the lower the Abbe number. The Abbe number is a very important parameter we use to measure the sharpness of the lens, which means that if the refractive index of the lens is high, that is to say, the sharpness of the lens is lower. If you have higher degrees, you can prioritize thinness and choose a lens with a higher refractive index, but don't overdo it.
Men's clear glasses are a fashion item.
A clear glasses frame is not only for a schoolgirl. Clear and transparent design more feel cool and refreshing in scorching summer. At the same time, it will not cover the facial features too much, making the face more delicate and clean. Small pure and fresh picture frames tie in some of the clothes of literature and art naturally. Therefore, the scope of use of clear glasses is very limited, only suitable for fashionable men.
