Titanium alloy
The definition of titanium alloy is relatively broad. As long as it contains titanium material, it can be called titanium alloy. Therefore, the quality and grade of titanium alloy glasses frames are uneven, and the component of titanium alloy has a direct impact on the price of titanium alloy glasses. Titanium alloy glasses are made not to reduce the cost, but to improve the application performance of the material.
Be careful to choose driving sunglasses.
Many people take it for granted that the darker the color, the better its UV protection. The function of filter the ultraviolet ray of the sunglasses is concerned with the film of plating only. Especially for long-distance drivers, wearing sunglasses that are too dark can make eyes more tired. And entering dark areas such as tunnels from the strong sun is more dangerous.
Some drivers are slightly myopic, but when they wear sunglasses, there's a problem: their eyes are more likely to tire and the vision can deteriorate, just like driving at night. So, if the slightly myopic drivers want to wear sunglasses, they must be equipped with a myopic degree of the lens.
Should I wear driving glasses at night?
In fact, it is not safe to use any colored lenses while driving. You might consider how much color plays in your average driving experience. Red, yellow, green, orange traffic signs, and other vital signs are designed to remind you to pay attention to safety signals and directions while driving. However, if you see everything turn yellow, you may miss a sign and end up making the wrong decision at the traffic light, or worse, an accident.
Another disadvantage is that they do not have a prescription. If you are looking for a pair of standard night driving glasses on the market, you will find that most of them are standard over-the-counter glasses. To have night-driving glasses that can correct vision, you must customize them in an optical shop, and the price is much higher. Under the hype of the night vision feature, you can expect the cost of prescription night driving glasses to be too high. You can find more information about how prescription glasses work on our blog!
The design evolution of progressive lenses
Spherical and aspheric designs
The design of the front surface of the far-use area of the early progressive lens is similar to that of the ordinary spherical single vision lenses, so it is called a spherical progressive lens. Since 1974, the front surface of the far-use region of the lens is designed to be aspheric by designers, which not only reduces the peripheral aberration but makes the lens thinner, lighter, and less powerful.
Hard and soft design
For hard design, the channel is short, and the gradient is large. The near-use area position is high. The effective visual area of remote and near-use areas was larger. Peripheral astigmatism is relatively concentrated. Because surrounding astigmatism increases rapidly and the distribution is dense, the curve effect is more obvious. The gradient area is narrow. It is more difficult and takes longer for wearers to adapt.
Lenses with soft designs have slower gradients, longer gradients, and wider gradients. The angle of rotation of the eye from the far area to the near area is greater. It's easier to get used to. Compared with the hard design, the effective visual area of the far and near use areas is smaller, and the location of the near use area is lower.
Single, diverse, and individualized design
Initially, the progressive lenses used a single design, in which each basic curve was scaled equally and a luminosity combination was added within the range of its semi-finished lens blanks. The steepest base curve uses the same lens design as the flattest base curve. Lenses designers quickly realized that the overall performance of the lens could be improved by microcustomizing the lens design, leading to progressive lenses with multiple designs. This kind of design is called diverse design. By the mid-1990s, there was the emergence of individualized lens designs. In addition to using different gradients, these first individualized lens designs used steeper baseline curves with a slightly larger approach area to compensate for increased magnification and reduced field of view.
Symmetrical and asymmetric design
There is no difference between the left and right eyes in the symmetrical design of progressive lenses. As the eyes turn inward when they see near objects, the gradual gradient area gradually tilts to the nasal side from top to bottom, so the left/right progressive lenses should be rotated clockwise/counterclockwise respectively during processing. An asymptotic lens with left and right eye divisions is called an asymmetric design. The gradient is gradually and moderately inclined to the nasal side from top to bottom. The refractive force, astigmatism, and vertical prism of the two sides of the left and right gradient of the asymmetric design lenses are basically similar. At the same time, considering the characteristics of eye movement parameters in binocular vision, the peripheral aberrations of the corresponding positions of the left and right lenses were appropriately balanced to improve the visual effect of the wearer.
Choose a good frame material
Each pair of glasses has its own characteristics and highlights. The frame itself is an ornament, playing the role of beautification. Today's plate spectacle frames are particularly popular with all kinds of people. Work is complicated and delicate, and design is diverse. Importantly, color and luster are good, not allergic. And it doesn't fade. It is also a high-grade frame. Both the grade and the design are very advantageous. Many brand glasses are made of plates. Some are made of high-grade plates. The appearance is beautiful and stylish.
Problems you may encounter when wearing your glasses.
The glasses are too tight. They clamp to the temple. Glasses slip easily. Too long or too short at the bend, and there are too small contact areas of the nose pad. Glasses are too far from the eye, and the lenses are crooked or asymmetrical. These are some of the problems you may encounter when wearing glasses.
What Are Progressive Lenses?
Traditional eyeglasses are usually single vision lenses with one prescription. Progressive lenses are multiple with three prescriptions in a pair of eyeglasses. Progressive lenses let you see comfortably at different distances, allowing you to see close, near, and far without changing your glasses. There are other kinds of multifocal lenses like bifocals and trifocals, but progressive lenses differ because of their smooth transition between prescriptions.
Bifocals and trifocals work similarly to progressive lenses and feature either two or three prescriptions in a pair of glasses. These lenses have definitive lines separating the prescriptions. However, progressive lenses don’t use these lines and allow you to easily transition between prescriptions.
Hence, in the following section, we will show you 6 different types of progressive lenses.
