One of the first people credited with inventing glasses was an English friar in the 13th century, Roger Bacon. In his Opus Majus (c. 1266), he outlined the scientific principles of the use of corrective lenses. Some writers believed that monks or friars possessed secret knowledge about glasses, which they later disseminated around the world. Most famously, William Molyneux wrote in his Dioptrica Nova (1692). Unfortunately, there is no evidence that Bacon ever applied his theoretical knowledge of perspective (optics).
Square face with round glasses
The square face belongs to the type of facial lines or tough, which looks a bit unnatural. For this type of face, it is best to choose round glasses because a round shape can make your facial lines softer and add a little femininity. The most suitable glasses for a square face are round, but the size of this round is also very particular. If you have a wider face, it is better to choose larger glasses, which can better modify the face and make the face smaller.
Disadvantages of contact lenses
They require more care than glasses. If you don't clean your contact lenses properly, or if you don't wash your hands before touching them, you could get a serious eye infection. Wearing contaminated contact lenses not only causes damage to your eyes but causes inflammation. If you have high astigmatism, your vision may become blurry when the lenses rotate. And there are a lot of contact lens health risks. There is a lot of news exposed that many informal manufacturers use fake or shoddy materials to make contact lenses, especially for the so-called beautiful contact lens, there are more risks in dyeing and health. The damage to the eyes is unimaginable.
What is the cheapest way to buy prescription glasses?
After the examination, you will bring your optometry sheet and go to the optician to match your glasses. Note that the optical shop has professional qualifications. The refractive index of the resin lens, such as 1.49, 1.56, 1.61, 1.67, and so on, mainly depends on the degree. If the degree is not high, 1.56 will do. In addition, the sophisticated store will also measure the nose height, nose width, the distance between the eyes and ears, and the forward angle of the frame, which are also indicators of whether the glasses are comfortable to wear. It is recommended to try them on after they are fitted, and the time to try on them should be longer, so as to determine whether the glasses are suitable.
How to Tighten Glasses by Yourself
After your glasses being used for a while, they will become loosen. In this situation, you may want to ask for a professional optical person to adjust or tighten it. It would be a way but with some inconvenience. So, you can also choose to tighten glasses by yourself.
Why the glasses will become loose? It can be caused by various reasons. Most people wear and remove their glasses several times every day. The back and forth movements of the glasses’ arms will increase the possibility that they will become loose.
If the glasses become loose, you can choose to tighten them by adjusting the temple arms. Most eyeglasses have a screw located at the temple hinge on both sides. To tighten glasses by yourself, you can choose to tighten this screw to make your glasses more comfortable or prevent them from slipping down your nose again. You had better check these screws periodically so you can tighten them before they fall out.
Characteristics of titanium frames
Titanium is widely used in the eyewear industry because it is not easy to deform, fade and has strong stability. The glasses frame made of titanium can highlight the noble taste and elegant temperament. The glasses frame made of titanium can be divided into pure titanium, titanium alloy, and beta-titanium frame three kinds. To learn about titanium frames, how to identify pure titanium frames?
Titanium frame has the benefits of low density, high strength, good mechanical properties, and strong corrosion resistance. The frame is very light and not easily corroded by moisture. However, due to the poor process performance of titanium alloy, machining is very difficult, the glasses frame made of hydrogen, oxygen, nitrogen, carbon, and other chemical impurities are more absorbed. The wear resistance of titanium alloy is relatively poor, and the production process is relatively complex, so the cost is relatively high and the workmanship is relatively complicated when using this material to make the spectacle frame. The price is much more expensive than the common spectacle frame.
The origin of aspheric lens
The Visby glasses, unearthed in Gotland, Sweden, are the earliest aspheric lens found. The Vikings in the 11th century used it as a magnifying glass, and some of the best ones were made of silver, making them look like handicrafts. In 1667, Francis Smethwick grinds the first high-quality aspheric lenses and presents them to the Royal Society. That's a telescope with three aspheric elements. In 1956, Elgeet, which originally designed and manufactured optical instruments for the U.S. Navy, produced the world's first mass-produced aspheric lens for photography (Golden Navitar 12mm F1.2) for a 16mm film machine. Today, aspheric lenses are found in everything from tall telescopes to missile guidance systems to camera lenses. In the glasses we wear, the aspheric lens is familiar to consumers.