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.
Transitions® Photochromic Lenses
When you step outside, it immediately begins to darken. The lenses help prevent harmful blue light from digital devices, screens, and sunlight to help reduce glare and prevent eye strain. They have the function of 100% UV blocking,anti-reflection treatment with blue light protection. They can constantly adapt to changing daylight conditions to reduce excess light and optimize color contrast and polarized light to prevent dazzle. They filter out excess light to provide maximum comfort. And provide high contrast and minimize glare. They provide increased color recognition and depth perception.
How much should a pair of prescription glasses cost?
Speaking of glasses, everyone's first feeling may be that it is not cheap to have a pair of prescription glasses. Just such a small pair of glasses, ranging from a few hundred dollars to a few thousand dollars. Why is the difference so big? So some people go online to buy glasses for dozens of dollars as if they look the same. But is it actually the same? There are a lot of differences between the glasses for dozens of dollars and for thousands of dollars, apart from the price. Also, you should be responsible for your own eyes.
Better glasses brands will adopt better designs to ensure beautiful appearance and structural safety, and have stricter quality standards. At first, these glasses are not cheap because the cost has increased a lot. In addition to the brand, different materials, process requirements, and mass production scale will also affect the cost and thus the final selling price. As for the question of what price glasses to choose, my suggestion is to choose the high-priced one within your budget. So, to choose a suitable pair of glasses, what aspects need to be considered?
Why are rimless glasses so expensive?
Although the overall volume of materials selected for rimless glasses is a little less, the special structure of rimless glasses requires much higher physical properties (flexibility, surface texture, etc.) and processing accuracy than TR, PEI, and other materials. Rimless glasses require higher quality lenses. For example, lens materials with a refractive index of 1.56 tend to be brittle for rimless glasses and should be chosen with caution. Generally speaking, the time of processing about three pairs of half-frame glasses is equal to the time of processing of a pair of rimless glasses.
How to Test Computer Glasses (Clear Glasses)
First, we will show you how to test computer glasses with clear glasses.
1. Ask for Blue Light Glasses Brand Spectrum Report
To find out whether your blue light glasses are the best computer glasses, you should contact the company you bought them from and ask for a spectrum report. It will show you how much blue light your computer glasses can block.
After sending the spectrum report to you, you should make sure that your computer glasses are able to filter at least 30% blue light, otherwise, they are unsafe.
2. Use the Lens Reflection Test
As for how to test computer glasses, you can use the lens reflection test. You can see what color the light is that reflecting off the lenses.
If it reflects the blue light, they are filtering some blue light. If the reflection is violent or purple, the computer glasses may be not effective.
This is a good way for you to perform a blue light test at home.
Heart-shaped face with angular glasses
The heart-shaped face is also a common face shape in daily life. This face shape is somewhat similar to the inverted triangle face shape. Generally, the chin is a relatively sharp face shape. For this type of face, the most important thing is to modify the cheekbones above the nose to highlight the slenderness of the chin. Therefore, it is better to wear a pair of angular glasses, which can effectively modify the facial lines and look more perfect.
Glasses for heart-shaped faces
This type of face has a wide forehead, broad cheekbones, and a pointed chin. It is called a heart-shaped face. The upper part of the heart-shaped face is relatively wide and flat, and the lower part of the line is uniform and smooth. The facial line, the proportion is very soft, giving a person an intimate intuitive feeling. Wearing longer or rimless glasses for this face shape will make you look cute.