There are three processes for resin-changing lenses.
The incorporation method, known as bulk polymerization, is similar to the method of glass lens, that is, one or more photochromic dyes are directly incorporated into the polymer monomer of the substrate for bulk polymerization, and the lens formed after curing will change color. Discoloration dye is completely integrated into the resin lens substrate, so the lens made of color persistence is very good.
The uniformity of discoloration and the depth of color after discoloration are highly related to the thickness of the lens. Because the thickness of the lenses at all levels is different, there will be a color difference between the depth of discoloration and the uniformity, and the uneven phenomenon of high brightness is more obvious.
The film type is known as the coating method. It is the chromatic resin lens by coating or dipping in a layer of chromatic dye on the base of the resin lens. Because the coating covers the surface of the lens, the color uniformity is good. The coating, which is only about 0.05mm thick, does not provide enough molecules to make the lens dark enough, so the color is relatively less dark, and the discoloration lasts slightly longer.
Infiltration, known as the penetration method, is to use the principle of penetration, through the thermal diffusion method to make the color dye permeate the surface of the resin lens sheet material, with diffusion depth up to 0.15~0.20mm. The lens has a constant color change characteristic. There will be no inconsistency between the center and the surrounding color as the luminosity gets darker. The color-changing resin lens made by infiltration type has the benefits of uniform color-changing, small color difference, fast and thorough color-fading, which is the mainstream of color-changing technology at present.
1.67 vs 1.74 High Index Lenses: What Are Their Differences?
In this section, we will show you the differences between 1.67 high index lenses and 1.74 high indexes.
- 74 high index lenses are thinner and lighter than 1.67 high index lenses.
- 74 high index lenses are expensive than the 1.67 high index lenses.
- Both 1.67 and 1.74 high index lenses can reduce the eye distortion caused by strong prescriptions, 1.74 high index lenses perform better than the 1.67 high index lenses.
- As for the color of lens, both come in clear, gray-tinted and brown-tinted, but only 1.67 high index lenses come in Transition brown or gray.
- 74 high index lenses are better for those looking for the thinnest lens possible. So, patients with extremely strong prescriptions chooses this.
- 67 high index lenses are better for those looking to save money or those who do not have extremely high prescriptions. They are also the only choice if you are looking to get Transitions.
From the above information, you can find the main differences between these two lenses are price, thickness, weight, color options and general appearance. Most people who choose 1.67 high index lenses generally either do not have an extremely high prescription or are shopping on a budget. 1.74 high index lenses, on the other hand, are the thinnest and lightest plastic lenses currently in existence.
Shorter lens beam
When you choose a glasses frame for kids, you must pay attention to that the lens beam must be short. The size of the lens beam stipulated by the national standard is 13~22mm. As a child, it should be controlled under 18mm. Otherwise, the position stability of the glasses will be poor.
Finally, they can not casually wear other people's glasses. The strength of each person's glasses, the distance between the optical centers of the two lenses, the length of the temple are different. So they can not casually wear other people's glasses.
Tortoiseshell frame
Tortoiseshell frame glasses can be said to break connotation completely, and this is a very stylish and slightly exaggerated style. It is recommended that fair-skinned, trendy hairstyle and stylish clothes should be worn by boys. After all, if you want to wear stylish tortoiseshell frame glasses, you need clothes and hairstyles to complement them. And if only wear the tortoiseshell frame glasses may not look good.
Recommended Glasses for Heart Shaped Face
Wayfarers frames: to balance out a wider forehead is by finding frames that have wide, prominent endpoints that extend out past your temples. This can draw the gaze up and away from your cheekbones, making your eyes the focal point. So, the wayfarers frames are recommended.
Cat-eye frames: if you do not know how to choose the best glasses for heart shaped faces, you can try the cat-eye frames glasses. They can be quite versatile and help contour your face, either balancing or highlighting prominent features.
Aviator frames: the last glasses for heart shaped face we want to recommend is the aviator glasses. They can work to draw the eye downwards and flatten the bottom part of your face. The aviator frame glasses can also add a balanced look and soften prominent angular features.
What is a progressive lens?
Progressive multifocal lenses are lenses with different upper and lower powers for seeing far above and below for seeing near. The distance from the fixed far power above the lens to the near power fixed below the lens does not change suddenly, but a gradual transition between the two through the gradual change in refractive power. Compared with ordinary lenses, there are many advantages. The appearance of the lens is like a single vision lens, and the dividing line of the power change is not visible. Not only is the appearance beautiful, but more importantly, it protects the age privacy of the wearer, and there is no need to worry about revealing the age secret due to wearing glasses.
Since the change of the lens power is gradual, there will be no image jump. It is comfortable to wear and easy to adapt. So it is easy to be accepted. Because the degree is gradual, the replacement of the adjustment effect is gradually increased according to the shortening of the short distance. There is no adjustment fluctuation, and it is not easy to cause visual fatigue. Clear vision can be obtained at all distances in the visual range.
Such a pair of glasses meets the use of long-distance, near-use and various distances in the middle at the same time. It is especially good news for teachers, doctors, music workers, and computer operators, because these people not only need to see far and near objects clearly, but most of the time they also need to be able to see middle distance objects such as blackboards, piano scores, and computer screens. . This is not possible with any lens other than progressive lenses.
What effect does a lens with the hard film have?
In order to improve the wear resistance of the lens, it is necessary to coat the surface of the lens with hard film. At present, silicon atoms are used to stiffen the membrane, that is, the stiffening solution containing organic matrix and inorganic superfine particles including silicon element is used to make the hard film have toughness and hardness at the same time. Because the common resin lens is far easier to wear than the glass lens, so the addition of hard film is mainly used for resin lens. It is usually applied to the front surface of the lens, and the anti-wear ability of the resin lens with the film will be enhanced a lot, and the light permeability will be strengthened.
