Refractive index of spectacle lens
It is generally believed that the higher the refractive index, the better the spectacle lens. Such spectacle lenses are relatively thin, and of course, the price is a bit expensive. When the refractive index increases, the direction of the light entering the lens will change greatly, the focus will move to the lens, the focal length will be smaller, and the diopter will become larger. In order to keep the diopter unchanged, it is necessary to reduce the curvature of the lens, that is, to reduce the curvature of the mirror surface, so that the thickness of the lens can be reduced. This is why the larger the refractive index, the thinner the lens is. Under the same premise of other things, the larger the refractive index, the thinner the lens, the lighter and more beautiful the lens, and the higher the price, but the larger the refractive index is not the better.
How to stop glasses hurting behind ears?
When adjusting glasses to the optical shop, you can let the staff check if the bending hook is flat. If there is a problem, put it on the polishing machine. The most important thing is that when adjusting the glasses, the height of the glasses temple should be adjusted according to the shape of each person's face, to further increase the comfort of the glasses. Furthermore, if you do not want to go to the optical store, you can make the glasses temple a little loose at home or put a little cotton or paper towel in the ear to prevent friction. You can buy soft eyewear online or at an eyeglass store to prevent ear friction and injury
What style of glasses is suitable for round faces?
The model of cat-eye glasses is niftier, with a more retro effect, so the fashion sense is strong, which can highlight the personality of the person. The glasses can modify the face, suitable for the girl with a round face. If you have a round face, it is recommended that you choose a pair of glasses with thick frames, which cover your face more and make your face look smaller visually. They fit all kinds of face shapes, especially round faces because they give people a visual impact, and they reduce the impression of face shapes.
How to Choose Glasses for Long Face?
Bold shapes and eyeglasses with decorative details are also a smart choice since they help draw attention to your eyes and can add width to your face. Be sure to avoid narrow or rectangular shapes, which can make your face appear longer.
Square glasses: if you have a long face, you can try square glasses whose sharper corners can help to balance out the length of your face and complement your narrow features. Choose frames that are slightly wider than your cheekbones to make your face appear broader.
Two-toned glasses: if you have a long face shape, the two-toned glasses would be a good choice. The color-top frames create an optical illusion that draws focus upward toward your eyes rather than to the length of your face.
Benefits of Blue Light Glasses
In this section, we will show you the benefits of blue light glasses.
- Relieve eye discomfort with blue-light blocking glasses. Excess device usage can lead to computer vision syndrome or digital eye strain. Blue light glasses can enhance your focus and reduce eye strain, resulting in making your eyes feel less tired and improving productivity. Another way to reduce eye strain is to make sure you take regular breaks from the screen.
- Blue light glasses can affect your sleep. Blue light has a high energy frequency that can increase alertness and delay the body’s release of melatonin, which helps induce sleep. In general, you had better not use blue light devices one to two hours before sleep. Blue light glasses can reduce the impact of blue light, enabling you to use your devices before bed and still get a good sleep.
- Blue light glass can help reduce the likelihood of Age-Related Macular Degeneration. AMD is a leading cause of blindness. Blue light blocking lenses can help avoid or delay this condition by preventing blue light from impacting your eyes.
Of course, besides those benefits, there are some other benefits of blue light glasses. For example, blue light glasses can relieve headaches.
What is the processing technology to make the lens thin?
For myopic lenses, the larger the diameter, the thicker the edge. Therefore, for customers with high myopia, we will recommend frames with smaller ring diameters, so that the edges of the processed lenses will be thinner. The edges of farsightedness lenses are already very thin (convex lenses are thick in the middle and thin on the sides), and the key determinant of lens thickness is the center thickness. In addition to the refractive index, which affects the thickness of the farsightedness lens, the influence of diameter is more important. Therefore, for patients with farsightedness, the most effective way to make lenses lighter and thinner is to choose a smaller frame and then customize a pair of lenses with the right diameter.
Does it take time to adjust to progressive lenses?
How long should it take to get used to progressive lenses? I have never worn glasses before.Progressive lenses were developed to allow easy switching between near and far views. Progressive glasses are divided into four parts. The upper part is the far-light region. The lower part is the near-light region, and the middle part is a variable light region. From top to bottom, if the hyperopia film is gradually increased and the myopia film is gradually decreased. The middle variable area is on both sides of the astigmatism area. Because of the prism effect, when you see things, through this area, the object will be blurred, and the eyes will feel uncomfortable. If the height of the frame itself is very small, the transition zone of progressive multi-focus is very narrow, and the eyes may not adapt to the sunglasses. The current design of progressive lenses is still not mature. Imported brands are relatively stable but expensive, and domestic brands are not mature in design. For various reasons, progressive glasses may be difficult to adapt to wearing.