Eyeglasses String Holder Straps Cord 4 Premium Eyeglass Chains for Men Women
The eyeglasses cord is equipped with a progressive eyeglasses belt ring protection mechanism to completely prevent your eyeglasses from falling. The eyewear strap can be held close to different types of eyewear temples. This cable holder is perfect for small, wide arms. They have an eyewear chain and string with an adjustable design, and an eyewear lanyard comes with a surprise gift. They provide a lifetime warranty, so you can rest assured to buy.
The oval shape is suitable for all kinds of frames.
Women with oval face shapes are very in line with Oriental aesthetic standards of beauty face shape.All kinds of frames are suitable, just pay attention to the size of the frames should be proportional to the size of the face. Especially female ellipse face, appropriate chooses the frame of any design but had better not use a straight-line frame, namely too tall too flat frame. All kinds of frames are suitable. Just pay attention that the size of the frames should be proportional to the size of the face. Especially women with ellipse faces can properly choose the frame of any design, but they had better not use a straight-line frame, namely, too tall too flat frame.
What is blue light?
Our daily lives are inseparable from mobile phones, computers, tablet computers, and other electronic products. Many people's eyesight is also going downhill due to long-term exposure to strong light electronic screens, and their eyes are more or less potentially adversely affected. It is found that many optical stores sell blue light filter glasses, which have the function of blocking 99.9% UV and scattered blue light, alleviating visual fatigue. They claim that these glasses can block short-wave blue light emitted by electronic products such as mobile phones and computers, and even prevent age-related macular degeneration so they are much sought after by consumers. The price of these so-called anti-blue-light glasses varies greatly, ranging from dozens of dollars to several thousand dollars. Do these blue light blocking glasses really have so many magical functions?
The natural light seen by the human eye is composed of a spectrum of different colors, including red light, orange light, yellow light, green light, blue light, indigo light, purple light, which gives people a visual feeling of white. Different wavelengths present different colors visually, and the shorter the wavelength, the higher the energy. At present, products with electronic screens such as computers and mobile phones use LEDs and other materials to emit light mainly in three colors of red, green, and blue, and blue light accounts for the main part. Blue light belongs to the range of visible light, belongs to short waves. And the wavelength is between 400 nanometers and 500 nanometers, which is close to ultraviolet and carries a large amount of energy. And this part from 400 nanometers to 450 nanometers is called high-energy short-wave blue light.
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.
Design principle of aspheric lens
Early optical lenses use spherical lenses. Because the glasses were small round frames, the problem of lens edge aberration was not paid attention to. It wasn't until large frames became popular that the problem became apparent. For the spherical lenses, aberration cannot be corrected with the combined lens. Only a few variables of the lens can be found to reduce aberration and improve clarity. Aspheric lenses are designed to reduce the aberration of optical correction lenses and to make lenses flatter and reduce lens magnification. We can get clearer, thinner, lighter-quality lenses. Thus, aspheric lenses are used to reduce aberration and astigmatism to a minimum, close to the natural vision of the naked eye. The spherical aberration can be reduced by changing the curvature of the edge. The refraction in the central region is high and decreases evenly toward the edges.
It is an online glasses supplier. They have eyeglasses, RX sunglasses, and sunglasses. LEOTONY was founded in 2016 in Seattle, Washington, by a group of passionate, intelligent, and professional young people who wanted to make the most suitable glasses for fashion, white-collar workers, and students. The company's philosophy is to provide the healthiest and most stylish care for the eyes.
Blue light and anti-reflective lenses
They reduce the potential for cumulative damage to the eyes.Allowing the beneficial blue light through improves clarity, they reduce glare and reflection. They can improve your visuals and reduces eye strain and nighttime reflexes. They can reduce the symptoms of computer vision syndrome, including eye strain, eye strain, and headache.