What is the best lens material?
MR stands for Mitsui Resin, a raw material for optical lenses made by Mitsui Chemicals in Japan. It is the first high refractive index lens material produced by polyurethane technology in the world. It has the characteristics of high refractive index, high Abbe number, low specific gravity, high impact resistance, and so on. MR series material, with high impact resistance, good tensile strength, and minimal internal stress, is very suitable for the unique design of lens products, like rimless glasses and high bending lenses, etc. At the same time, it has good processing, dyeing, and weather resistance.
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.
Advantages of Progressive Lens
Continuous and clear vision throughout the entire process is the advantage of progressive lenses. Because the added value continuously increases gradually in the gradient zone, the wearer can obtain continuous clear vision from the far point to the near point through the gradient lens under the appropriate head position. In line with physiological optics, better adaptation. The appearance is better than that of double-lens and triple-lens. There is no dividing line of sub-sheets, and there is no ring-shaped blind zone and invisible sub-sheets.
Find the right size
The right glasses should sit comfortably on the bridge of the nose, not pressed against the forehead or cheeks. But they don't stay at the tip of the nose for so long that they slip while squinting or wrinkling your nose. The fit of the nose determines the distance between the glasses and the face. A proper fit should allow the lens to be between 14 and 24 millimeters away from the eyes. When you want to find glasses that fit, don't clip, don't slip, and don't lead to discomfort, you have to find out the size you need.
Pay attention to the color of your blue-blocking glasses.
For children, their lenses are relatively clean and clear, and the blue light transmittance is higher than that of adults, which is more harmful to the eye. On the complementary color principle of optics, a good pair of blue light glasses should not be deep orange, but light yellow. The complementary color to cyan is orange. So, in order for the glasses to absorb blue light and filter it out, they must appear blue's complementary color yellow, otherwise, they violate the optical principle of absorbing blue light.
Beta titanium
β titanium refers to a particle titanium material that is completed by delayed cooling at the zero bound point state of titanium and does not belong to the alloy. Practical applications will often be processed into alloys to increase their applicability. Although the purity of β titanium is not comparable to pure titanium, its strength, fatigue resistance, and environmental corrosion resistance are better than pure titanium. It has higher strength than pure titanium and other titanium alloys, and the corrosion resistance is stronger and has better elasticity, It is not easy to deform, and is lighter.
The Disadvantages of Aspheric Lenses
Here, we will show some disadvantages of aspheric lenses.
The aspheric lens has a relatively small light area. When the eyeball rotates around, it will blur a little when looking at the outside through lens edge. In other words, the visual range of the line of sight becomes smaller.
Human’s eyeball is spherical and the eyeball rotates to the edge. Through aspheric lenses, the objects near the eye appear protruding.
