Basic principles of progressive lenses
The surface of the progressive slice is divided into five regions. There are far, middle, and near optical areas. They are respectively corresponding to see distant objects, middle distance objects in the near distance objects. One pair of glasses is multi-purpose. In appearance, it is not very different from regular lenses. There is no clear dividing line. Distal use area: The area above the progressive slice is the distal use area, which is used to correct the distal refractive error. Proximity area: from the matching lens cross down, the refractive power of the lens continuously increases the positive degree, which is used to see close objects. Gradient area: The channel connecting the far and near areas. It is an area of regular change from top to bottom, used for transitioning and seeing objects at intermediate distances. The length of the gradient is very important for the wearer's adaptation. The rate at which the degree of gradient changes is called gradient. The gradient can be uniform or variable. Peripheral area: Changes in the surface curvature of the lens will lead to aberrations in the peripheral areas on both sides of the lens, mainly astigmatism and prism effect, which will interfere with a vision to a certain extent, resulting in blurred vision or distortion. And it will affect the wearer's adaptation to the progressive lens.
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.
Benefits and disadvantages of rimless glasses
Rimless glasses are more stylish colorful, and comfortable to wear, greatly easing the pressure on the bridge of the nose and eyes, and because there is no frame limitation, the wearer's field of vision is wider. They are loved by young people. After a period of time, the screws at the hole are easy to loosen. The wearer should often tighten the screws.(https://www.koalaeye.com/collections/rimless-glasses)
The quality and reputation of the store owner are affected. And because there is no support bracket, when the glasses are placed on a hard object, they will directly contact the lens, which is easy to cause lens wear. In addition, when the rotation or torque force is encountered, the force will directly act on the lens, so when the force is too large, it is easy to cause damage to the lens.
Are rimless glasses in style 2022?
Now the glasses design concept changes with each passing day. The glasses are more and more in line with the aesthetic requirements of modern people, adding style and elegant demeanor to your clothing collocation. Rimless frames are not obvious either in appearance or weight, relieving some of the distress caused by myopia. Rimless glasses not only give you a wider view, but reduce overall weight, and have become a favorite of many fashion trendsetters. Are these rimless glasses your style?
Why are titanium glasses so expensive?
Strong and Durable. They are widely used in aerospace technology, jewelry, surgical instruments, and other fields. It is the most progressive material in the eyewear industry. Titanium is a very hard, lightweight metal that is proper for eyeglass frames. With good hardness, high strength, the glasses are not easy to deform. It is not easy to scratch and wear and has good corrosion resistance and plasticity. It has a high melting point, corrosion resistance, and hard electroplating. Titanium can be made into memory metal, which means it can bend and return to its original shape. Hinge is not easy to break, having rust resistance, impact resistance. When it's used in glasses, it fits the bill.If you've ever broken a frame, titanium is possible the best material for you.
The arm length is an important part of the size of the glasses.
Spectacle frames are standard optical products. Just like people's clothes and shoes, they all have their own size. Usually, specs for the size of the glasses are on the inside of the temple, on the bridge of the nose, or on the label. In general, the frames of the glasses are marked with the width of the frames, the width of the bridge of the nose, and the length of the arm. For example, the inner side of the temple is labeled: 52口 18-135, indicating the lens width of 52mm, the width of the nose bridge of 18mm, and the arm length is 135mm.
Why do glasses with the same prescription feel different?
The old glasses 'remodeled' your eyes. Sometimes, all data on optometry and processing are accurate, and the spectacles equipped are in full compliance with the prescription for optometry, or the power of new spectacles is exactly the same as that of the old spectacles, but you will still be dizzy when wearing the new spectacles. This is because the old glasses 'remodeled' their eyes during long-term wear. For example, the old glasses used by some people have been severely deformed. The temples are no longer in the same plane, and the optical center area of the lens will deviate from the interpupillary distance measured by the glasses at that time. However, the wearer does not mention this situation, and the eyes gradually adapt to this kind of deviation. After putting on a new pair of glasses, you will not adapt to them.
