Roger Bacon
One of the first people credited with inventing glasses was an English friar in the 13th century, Roger Bacon. In his Opus Majus (c. 1266), he outlined the scientific principles of the use of corrective lenses. Some writers believed that monks or friars possessed secret knowledge about glasses, which they later disseminated around the world. Most famously, William Molyneux wrote in his Dioptrica Nova (1692). Unfortunately, there is no evidence that Bacon ever applied his theoretical knowledge of perspective (optics).
Advantages of Metal Frames
The metal frame of eyeglasses conforms to the use performance of the frame. They need the material to have high fracture strength, enough plasticity, toughness, and good elasticity. And after the disappearance of the external force, they can restore to the original shape. This is the regular demand for the high elasticity of the metal frame. They must be able to withstand the atmosphere and human sweat daily corrosion. Usually, the corrosion resistance of pure titanium eyewear will be better than other eyewear. Some glasses will have a variety of wonderful grinding designs, and the material must have high plasticity.
Types of Single Vision Lenses
Single vision lenses come in several different types including the 1.59 polycarbonate single vision, 1.57 mid-index single vision and polarized single vision.
1.59 polycarbonate single vision lenses are characterized by their durability and impact resistance. They often include an anti-scratch coating or anti-reflective coating. This lens is much lighter and thinner than a traditional plastic lens, and it blocks the sun’s harmful UV, offering maximum UV protection.
1.57 mid-index single vision lenses are thinner than regular plastic and moderately lighter and stronger. They come with an anti-scratch coating or anti-reflective coating. These lenses are an ideal option for people with relatively higher prescriptions. But they are thicker than the polycarbonate lenses.
Polarized single vision lenses are sunglasses that protect your eyes from light that bounces off smooth, highly reflective surfaces like asphalt, snow, and water. These lenses work by controlling certain light properties and limiting specific wavelengths. They boast a vertical filter that does not allow horizontal glare to pass through.
What Are Varifocal Glasses?
Varifocal glasses, also known as varifocals, varifocal lenses, or progressive lenses, have a gradual change in strength from the top of the lens to the bottom with multiple focal points in between. Unlike bifocals, varifocals glasses have no specific area of lens strength, but progressive lens zones.
As mentioned above, varifocal glasses have three different prescriptions in one pair of glasses, allowing you to correct near and far vision. So, they bring you great convenience since you don’t need to change the glasses frequently.
However, there are also some common problems with varifocal glasses and we will show you the disadvantages of varifocal glasses.
So, in the following section, we will show you the disadvantages of varifocal glasses.
The principle of the anti-fog lens
Ordinary lens materials and water are wet, so water vapor is easy to fog up on the top. If this wetting relationship can be broken, the water vapor can be prevented from fogging up on the surface of the lens. The anti-fogging film is a kind of film which can prevent or avoid water mist agglutination effectively. It is divided into organic film and inorganic film. The inorganic film is mostly used for building, car window glass fogging prevention. For lens anti-fogging, the organic film is more used. The method is to wipe, spray (with an anti-fogging agent, and so on).
What Are the Advantages of Progressive Lenses?
We have shown what the progressive lenses are in the above part. Do you know what the advantages of progressive lenses are？.
1. Only need a pair of eyeglasses. As mentioned in the above section, with progressive lenses, you just need a pair of eyeglasses and there is no need for you to change different glasses constantly.
2. No unsightly bifocal line. Progressive lenses come with the multifocal lens without a multifocal line. And there is a smooth shift in lens strength, you don’t have to deal with any sudden changes in clarity.
3. More comfortable. Due to no visible line, you might feel more comfortable with a progressive lens.
What are driving glasses?
Driving glasses refers to the glasses that are specially used for driving, with functions of anti-glare, anti-strong light, anti-rain and fog, anti-fatigue, and other functions. They are suitable for drivers in the day and night to wear glasses for vision protection, better-ensuring traffic safety. They are recognized as the driver's glasses, driver glasses.
