Design principle of progressive multifocal lens
For the same piece of the lens, the top is used to see far, the bottom is used to see close. The upper and lower degrees are different.
There is not a sudden change in the distance degree fixed above the lens to the near degree fixed below the lens, but a gradual transition between the two through gradual changes in refractive power, which has special benefits over common bifocals or trifocal lenses.
What Are Trifocal Lenses?
When you are over 40 years old, your eyes may become old, too. Your corrective lens requirements may become increasingly unique, Most people are familiar with bifocal glasses but unfamiliar with trifocal glasses. So, in this post, we will show you what trifocal glasses are.
Trifocal lenses have three different corrective lenses within one lens to offer you intermediate, distance, and near correction, all in one pair of glasses. The varying levels of correction cab are laid out in a couple of different ways to ensure the layout suits your unique vision needs and comfort level.
The near vision is to correct close-up vision, the intermediate vision is often used for card playing and staring at the computer screen fall with this range of vision, and the distance vision is often used for driving or looking at a whiteboard.
Glasses are tools to protect your eyes.
Wearing glasses can relieve eye strain. Myopia without glasses will inevitably lead to eyes easy fatigue, so the result can only be a deepening of the degree. After wearing glasses normally, the phenomenon of visual fatigue will be greatly reduced. For young people, because the eyeball is still in the development period, regulatory myopia easily develops into axial myopia. Especially for high myopia, the diameter of the eyeball before and after is significantly prolonged. If the myopia is rectified by wearing a normal lens from the beginning, this situation will be reduced or even not occur. If people with Myopic did not wear lenses in time, it will cause ametropic amblyopia. So if wear appropriate glasses, after a longer treatment, most eyesight will be gradually improved.
RIVBOS Polarized Sports Sunglasses for Driving
TAC Polarizing Lenses - RIVBOS lenses are made from cellulose triacetate (TAC) material. TAC has quality optical properties that prevent the shrinkage of PVA polarized light film and has high strength surface scratch resistance. They help restore the original color, eliminate reflected and scattered light, and provide perfect eye protection. Rivbos frames are made from durable TR90 material. These polarized sunglasses feature flexible, stress-resistant frames that are able to withstand pressure without breaking. Whether it's sports or casual, you can show off your unique style.
Features of TR90 Frame
It has the characteristics of wonderful toughness, crash resistance, wear resistance, and low friction coefficient, which can effectively prevent damage to the eyes and face caused by the fracture and friction of the frame during the movement. Because of its specific molecular structure, and chemical resistance, it is not easy to deform in a high-temperature environment. It's very elastic, and it doesn't deform. The use of thermoplastic materials in these frames provides pretty strength due to their flexible characteristics.
Is titanium alloy necessarily worse than pure titanium?
In the common case, the introduction of a titanium frame will have a detailed material label, what titanium and what material is it made of, such as titanium nickel alloy, titanium aluminum vanadium alloy, and so on.
The composition of titanium alloy determines the quality and price of the frames.A good titanium frame is not necessarily worse or cheaper than pure titanium.It is difficult to ensure the quality of titanium alloy which is very cheap in the retail market.In addition, titanium alloy is not to reduce the cost, but to improve the performance of the material.Usually, the memory frame on the market is made of titanium alloy.
Can clear lenses be polarized?
At present, there are no clear polarized lenses. A polarized lens is a thin film vertically arranged with silicon crystal coating placed inside the lens, just like a shutter, which covers the parallel light and only allows the vertical light to pass through. In this way, the glare from all directions can be eliminated, so it is clear and comfortable to wear. Transparent polyamide, the material of nylon lens, is a new variety of polyamide. The material of the nylon lens is mainly transparent polyamide. Due to the effect of the light filter, only light from a specific direction is allowed to pass through the lens, which filters the dazzling light from the sun on the water, land, or snow very well. It can not only make the landscape soft, clear, and natural but protect the eyes to a certain extent.
