The cost of an eye exam
If you have a Walmart Vision Center near you and you need a new or updated prescription, you can schedule your eye exam there. Some vision centers have independent optometrists who work in offices next to Walmart. An eye exam at Walmart costs about $73, depending on where you live. Call your nearest Walmart Vision Center to get the exact price of an eye exam.
Understand blue light correctly.
Blue light has been shown to affect the body's circadian rhythms, with too much exposure to it late at night from gadgets such as mobile phones disrupting a person's ability to fall asleep. Therefore, it is recommended that people limit screen time two to three hours before bedtime and set their devices to night mode to reduce glare, relieve eye fatigue and minimize blue light at night. However, as we learn more about blue light, not all of it is bad for us. Blue light has been found to play an important role in maintaining health, such as regulating the secretion of hormones in living organisms. Blue light helps prevent reduced night vision and has been shown to benefit refractive development in adolescents and minors.
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 choose blue light blocking glasses?
Nowadays, electronic products such as mobile phones and computers have become indispensable tools in our lives. While these high-tech products bring us convenience and fun, they also bring symptoms such as eye fatigue and myopia. Subsequently, blue light blocking glasses have also received everyone's attention. Anti-blue glasses are only suitable for people who use electronic products for a long time, not for people who are visually fatigued. Exposure to such unnaturally strong blue light for a long time every day, especially for teenagers and children, needs to pay more attention to the prevention of blue light. So, how to choose suitable blue light blocking glasses for kids?
Anti-blue light is necessary, but not all blue light can be filtered out, because blue light will interfere with the body's melatonin secretion after being over-filtered, thereby affecting sleep. Therefore, when choosing blue light blocking glasses, you should choose appropriately according to your own eyes.
For how to choose anti-blue glasses, consumers can distinguish from the color of the lenses. Generally speaking, a lens with a yellow color will have the effect of blocking blue light. But too dark lenses will affect the contrast sensitivity. Therefore, it is recommended that consumers choose moderately. In addition, consumers should also pay attention to whether the glasses products (lenses, frames) have conformity marks, etc. It is best to choose professional and well-known glasses shops to match glasses.
The birth of progressive lenses
In 1907, British optometrist Owen Aves first proposed the concept of progressive lenses and got the first patent of progressive lenses. In 1910, Henry Orford Gowlland designed and made a similar lens in Canada, but technical limitations prevented it from succeeding. In 1959, Bernard Maitenaz, a French optical and mechanical engineer, developed the first progressive lens, which was successfully put into the commercial market for the first time and became a milestone in the history of world optometry. With the development of science and technology, the design of progressive lenses has been greatly developed.
What are the characteristics of a titanium frame?
The so-called pure titanium, titanium refers to the purity of more than 99% of the titanium metal materials. To tell if a pair of glasses frame is pure titanium, we look at its purity. Because of the high melting point of titanium, lightweight, strong corrosion-resistance, used for the frame, they can wear for a long time, and will not let the bridge of the nose have a sense of pressure. But its disadvantage is that the material is soft, and only the relatively rough frame lines are made to ensure the stability and strength of the frame. Titanium frame has the advantages of corrosion resistance, acid and alkali resistance, high stability, good elasticity, good toughness, not easy to deform and fade. General glasses frame contains copper, so when we wear for a long time .it will produce verdigris, namely, copper sulfate. It is a toxic substance and is harmful to the human body. Because pure titanium tends to be soft, copper has to be added to make the frames more stable, which is why the frames have to be replaced over time.
Convenience and timeliness.
The essential carrier of Mobile applications is the mobile terminals. As the name suggests, these mobile terminals are not only smartphones and tablets but smart glasses, watches, clothing, accessories, and other kinds of personal belongings. They are part of what the human body wears and can be used anytime, anywhere. People can make full use of the fragmented time in life and work to accept and process all kinds of information on the Internet. They can no longer worry that they will miss any vital information, time-lapse information.
