What are keyhole glasses used for?
The keyhole distributes the weight of the glasses to one side of the nose rather than the top. It's a good choice for those with broad noses. Due to the lack of support at the top, the keyhole design will result in the frame being positioned lower than the saddle bridge frame. If you find that your saddle frame causes your eyes to be located just below the center of the lens area, you may try a wider frame or opt for a keyhole design.
What Is Polycarbonate Lens?
Polycarbonate was invented in the 1970s for aerospace applications and is currently used for the helmet visors of astronauts and for space shuttle windshields.
Polycarbonate lenses were introduced in the early 1980s in response to a demand for lightweight, impact-resistance lenses. Since then, polycarbonate glasses have become standard for safety glasses, sports goggles, and children’s eyewear.
Polycarbonate glasses come with a lot of features such as thin and light and they provide 100% percent UV protection and are up to 10 times more impact-resistance than plastic pr glasses lenses.
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.
How to protect rimless glasses?
With the continuous improvement of people's living standards, many people begin to pay attention to their quality of life. In the past, many people thought that wearing glasses was for correcting eyesight glasses, but now more and more people use them for decoration, and rimless glasses meet the needs of consumers. Because of its light structure, giving people a sense of fashion, so it is loved by many business people. So how do you protect your rimless glasses?
Agstum Titanium Rimless Flexible Frame
AGSTUM provides the best quality optical frames and sunglasses. Hand-ground materials and carefully designed to reflect that AGSTUM glasses have the true interpretation of excellent texture and perfect taste, showing a distinctive, outstanding, elegant, and noble temperament.
AGSTUM is committed to providing the highest standards of customer service to every customer. You can frame the lenses at your local optical shop. These frames come with clear lenses that won't hurt your eyes.
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.
Are titanium glasses frames worth it?
The maintenance cost of prescription titanium glasses is low. Apart from the durable feature, they hold their shape. It doesn't break on the ground. Even if the lens breaks, the frame will not break. You just need to replace the lens, do not have to pay for a new one. In other words, you don't have to spend a lot of time taking care of them, and you can make sure they last for years. It doesn't make your allergies worse and lasts for years. If you've ever broken a glass frame, titanium might be the perfect material for you.
