Single Vision Lens
Single vision is the most commonly used prescription lens. This lens type has a single field of view or a prescription ability of the entire lens and can be used to correct myopia (nearsightedness) or hyperopia (supervision). Some people need glasses to keep their distance and read. Instead of having a pair of single-vision glasses for each pair of glasses, bifocal or progressive glasses may be a more convenient choice. Unlike single vision, bifocal and progressive lenses are multifocal lenses with multiple focal points, such as distance and near distance. People whose prescription for spectacles list the numbers in the 'ADD' section require bifocals, progressive glasses, or reading glasses because your glasses need to add ADDitional to the distance prescription to see close distances.
How to choose blue light blocking glasses?
While trying it on, look at the electronic screen from a distance to see if it stimulates your eyes. Holding the glasses in front of a display screen or under an LED light to see if they reflect blue light on the surface of the lens. It shows that blue-blocking glasses can block blue light. The special blue light flashlight shines on the white cardboard through the lens, the blue light that passes through the blue-blocking lens is noticeably dimmed, while the blue light that passes through the normal lens is not changed at all, which is what the blocking blue light does. You can go to a professional eyeglass shop to detect instruments through the spectrum of professional authority, and the best blue light blocking rate is between 60%-70%.
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).
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.
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.
What Are High Index Lenses?
High index lenses are composed of a special plastic that is good at bending light. With this feature, high index lenses can be much thinner than standard lenses while having the same prescriptions.
So, polycarbonate lenses vs high index lenses, what are their differences?
Driving Glasses - Conant
Conant is a well-known lens brand and a famous trademark in Shanghai. It is a listed company, a high-tech enterprise in Shanghai. It is one of the largest suppliers of Chinese glasses in the world market. And it is an early enterprise in the field of resin lens production in China.