The style of prescription glasses
Choose the material, and then choose the style. The width of the appropriate frame should match the distance between the two pupils to ensure that the eye can pass through the optical center when looking at things. Choose the right style according to your face shape. Generally follow the complementarity principle, such as choosing square frames for round faces and round frames for square faces. After choosing the frame, you should try it on for a while to see if the weight is appropriate and the style is suitable.
The anti-reflection principle of the anti-reflection film
Anti-reflection Coating, known as anti-reflection membrane, is called anti-reflection coating in English, or AR membrane for short. The basis of anti-reflection is the wave and interference of light. The principle is: Two light waves with the same amplitude and the same wavelength are superimposed, then the light wave amplitude is enhanced. The two wavelengths and amplitudes are the same, but the superposition of wavelengths with different wave paths (similar to dislocation) cancels each other out. Therefore, the anti-reflection film plated on the surface of the lens uses this principle to make the reflected light generated by the front and rear surfaces of the film layer interfere with each other, thus canceling each other and achieving the effect of reducing reflection.
Pair is designed for children. There are only a few styles of frames, but there are hundreds of colors and patterns on top of the frames, and the top of the frame base can change colors, from pure pink to rainbow tie-dye to NBA logos. Pair also makes limited-edition tops and works with major brands like Marvel and Harry Potter to create themed styles that allow you and your children to showcase your personality. Each frame starts at $60, including standard prescription lenses, and the frames cost $25.
Is blue light blocking worth it?
There are two main problems with anti-blue glasses currently on the market. One is that the place to be prevented is not preventable, and the other is that people have color casts due to wrong protection and aggravate visual fatigue. Studies have shown that our eyes are the most intolerant of blue light in the 400-440 nanometer band. Therefore, current manufacturers mainly block blue light in this band when producing anti-blue glasses. However, the blue waveband of electronic products is between 450 nanometers and 490 nanometers, so most anti-blue glasses have little protection in this waveband. In addition, the blocking rate of anti-blue glasses is 20%~30% to achieve a good anti-blue light effect, but now the blocking rate of anti-blue glasses on the market has basically reached 80%~90%. All in all, these blocking blue light glasses cannot prevent the blue light in the 450-490 nanometer band, and their high blocking rate will also cause a color shift, which makes people more likely to have eye fatigue and headache.
In daily life, the intensity of blue light is low, not enough to cause damage to the fundus, so ordinary people do not need to wear anti-blue glasses unless they are working in extremely strong light conditions or working in special environments. To protect the eyes, it is more important for people to develop good eye habits. For example, wear a pair of suitable glasses and read insufficient light and at an appropriate distance. Avoid using electronic products for a long time. Take a break for 20 to 30 seconds every 20 to 30 minutes, and look at the distance regularly. If you have dry eyes while reading the electronic screen, remember to blink to 12 times per minute. It is best to wear sunglasses when outdoors.
Advantages of Plastic Frames
Plastic frame material is mainly various types of plastic polymer materials. With the characteristics of impact resistance, suitable for athletes to wear. The plastic used to make the frames can usually soften under the condition of the heating, and some plastic frames can be fine-tuned without heating. The plastic frames are not allergic and lightweight, making them suitable for children and people of all ages. And because the color is rich, and there are many styles. They become the choice of fashionable sunglasses. Plastic frame cost is low, and the process is simple. Because of its lightweight, plastic glasses frame is not easy to allergy. Because of its color and material characteristics, they become the fashion personage sunglasses or decoration choice.
Titanium is difficult to process.
Titanium is difficult to machine. Pure titanium is very soft and usually not suitable for use as titanium products, so other elements need to be rejoined. For example, ti-64, which is commonly used in the aviation industry, has to be mixed with many other elements to improve the performance of the metal.
Use your two hands to wear and take off the glasses.
When you pick and wear glasses, you need to grab the temples with both hands and take them off. When you pick and wear glasses with one hand, it is easy to cause deformation and loosening of the glasses. According to the convention of international glasses design and manufacture, you should fold the left temple first. When placing glasses, keep the convex side of the lens up to avoid scratches on the lenses.