How do you identify the refractive index of lens?
In reality, this problem is often a problem for optical shop practitioners, sometimes they worry about whether the manufacturer's lenses match the nominal value of the refractive index. We need a prop, and that's the camber. Because it can be used to measure the strength of the lens. The luminosity of the lens can be calculated by subtracting the curvature of the inner and outer surfaces of the lens. The curvature difference of a lens of the same luminosity is inversely proportional to the refractive index, that is, a lens with a higher refractive index only needs a smaller curvature difference to achieve the same luminosity.
How to buy glasses that have quality assurance online?
First of all, you need to find a good eyewear online store and determine if there is any discount information. Big glasses usually have preferential information, and there are certain preferential activities. Lenses are very important to us, so the best quality is good. The price can be considered as the average level because low-level lenses are best not to prevent damage to our eyes. The frame is not that important, and it is only used to support the lens. Choose a pair of good-quality glasses for this combination. Optometry is closely related to the quality of the glasses. If it's not accurate, your glasses must be substandard. If your optometry data is good, you will get a real pair of glasses. You need to make sure your optometric data is accurate, which is a process you must go through when wearing glasses online.
Silhouette Rimless Glasses
They provide a range of options for rimless, full-frame, and half-frame styles. Their optics lab allows personal prescription lenses to be mounted on any frame and sunglasses. Here, fashion and function come together in an ultra-light titanium eyewear frame, using exclusive hingeless polycarbonate lenses. Minimal weight, hingeless construction, and form combine timeless framing styles with different kinds of lens shapes and breakthrough technologies.
Benefits of MR Lenses
It is made of MR series material of Mitsui Chemical, Japan. The biggest advantage is that it is both thin and has good optical properties. Besides, the material has good impact resistance and toughness, so it is not easy to be deformed or broken. Wearing such lenses not only looks more beautiful, but clear and comfortable, and safe at ease. Using a lower density polyurethane material, the lens is lighter and thinner, making it more comfortable to wear. The higher machining success rate increases the processing efficiency and reduces the processing cost. The film compatibility and dyeing properties of MR™ are better than those of ordinary materials, which can improve the quality of functional lenses like photochromic lenses and myopic sunglasses. MR-8™ combines high refractive index, high Abbe number (for better imaging), and better processing performance, suitable for rimless, half-frame, and other glasses, which are less broken and safer. MR-7™ provides better dyeing performance, faster and more uniform color application, and can be used for myopic sunglasses. MR-8 Plus™ is safer and further improves the impact resistance of the lens while maintaining the high Abbe number of MR materials.
How to buy contact lenses online?
Choose the right contact lens for your situation. Base arc and degree need to be added in the hospital or optician shop to determine. Try not to buy according to the framed degree. Some businesses claim to have the lenses having South Korea's silicone hydrogel, with annual throwing. They are not to be believed, because the material characteristics of the silicon hydrogel are not capable of making long-time discarded type lenses. There are a lot of things to pay attention to in order to properly wear contact lenses. For example, a medical optometry sheet is the premise of attention. Each pair of contact lenses is marked on the package of the basic arc, diameter, water content, diopter, and other parameters. Only according to the optometry sheet, you can choose the correct basic arc, diameter, and diopter. At the same time, there is a certain distance between the glasses and the cornea.
How to buy plano lens?
You had better not buy off-the-shelf plano lens, buy by fixed matching, just like matching with myopic glasses. The price is much more expensive than the finished product. However, the quality of the finished glasses is not guaranteed, and the materials are also poor, which is not only not helpful to you, but harmful for a long time. There is no essential difference between degrees and workmanship technology for the lenses, what should choose is the brand lens film of the lens, and the transmittance of the lens, and the design technology of the lens, to buy a good lens (including smooth lens).
What symptoms does myopia have?
Myopia is a problem related to the eye's ability to focus on distant objects. The manifestation of myopia is that blurred vision at a long distance. But near-distance vision is good. Early myopia often has long-distance vision fluctuation and squinting when looking at distant objects. Because looking close need not or less use an adjustment, and set function is weakened correspondingly. Those with high myopic have poor far vision, often accompanied by poor night vision, floaters, and other symptoms. Changes in the fundus of the eye can occur to varying degrees. It can form irregular shape white atrophy spots and so on.