How to know if lens is polarized?
Make use of LCD screens. Point the glasses horizontally at the LCD screen and then rotate them upward by 45 degrees clockwise. If it is a polarized lens, it will show a change in color deepening. If it does not change no matter how you rotate it, it is not a polarized lens. You can borrow another person's polarized lens or have previously worn a known true polarizer, and place it crossover with the new glasses you want to buy. At this time, you should see the object clearly from the crossover part with your eyes. Then cross the glasses vertically and horizontally, and at this point, the opposite object should not be visible from the intersection. If this condition is satisfied, it means that a true polarized lens is being tested.
The first inventor of wearable glasses is not known. However, it was the Romans who first discovered the use of glass to enhance their ability to see small words, creating small magnifying glasses with spheres. The first known wearable glasses in history appeared in Italy in the 13th century. They were used mainly by monks, and became popular little by little during the Renaissance, as the technology improved. As their popularity grew, the Italian glasses spread throughout Europe, mostly within reach of the wealthy. Because learning was a prized attribute during the Renaissance, glasses were a status symbol of wisdom and prosperity. With the temple extending above the ear, the glasses are no longer required by hand.
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.
What Are Computer Glasses?
Computer glasses or glasses for computer are prescription glasses that are designed to wear when doing computer work. They allow you to focus your eyes on a computer screen. There are other activities such as playing piano or shooting requiring a similar custom fitting.
Glasses for computer use are also known as blue light glasses. They block blue light that causes eye strain due to prolonged viewing of digital screens. Blue light is part of the color spectrum, and everyone is exposed to it through sunlight.
The glasses for computer use have a shorter wavelength than other colors and are emitted by electronic devices such as smartphones, TVs, computers and more. The glare from blue light is what causes digital eye strain or other symptoms. But the glasses for computer can protect your eyes from the damage of the glare.
Depending on an individual’s vision and type of work, there are several options while selecting glasses for computer use.
Monofocal: Monofocal or single-vision glasses are designed for computer work so that they provide the appropriate optical correction for the working distance between the screen and the user’s eye. These glasses allow users to view the whole screen with a minimum up-and-down head movement. However, the disadvantage of the monofocal glasses is that both distant objects and reading materials that are closer than the computer screen will appear blurry.
Bifocal: When it comes to glasses for computer screens, the bifocal glasses would be a choice. Bifocal glasses can be prescribed so that the upper segment is set up for screen distance and the lower segment for work. The disadvantage of these bifocal glasses is that it will blurry if the objects are farther away than the screen.
Trifocal: These trifocal glasses for computers have lenses that combine a segment for far vision, another for near vision and the third one for at the screen distance. The disadvantage of these glasses for computer screen is the limitation to view areas.
Progressive lenses and single vision lenses
Single vision lenses are the most widely used optical lenses and are suitable for the general population.
Progressive lenses are suitable for below people.
① Myopia control lenses for teenagers. Progressive lenses are used to relieve visual fatigue and control the development speed of myopia.
② Anti-fatigue lenses for adults. Progressive lenses are used for teachers, doctors, people who use too much computer at close range to reduce visual fatigue caused by work.
③ Progressive lenses for Middle-aged and elderly people. A pair of glasses for middle-aged and elderly people to easily see near and far.
What Do Blue Light Glasses Do?
Blue light has wavelength and energy from 380 nm with the highest energy to 500 nm with the lowest energy. The violent and blue-violent rays are more likely to damage our eyes so these rays are also called harmful blue light.
The blue light can be from the sunlight, fluorescent light, LEDs, computer monitors, smartphones, and tablet screens. Long time exposure to blue light may cause eye strain and discomfort. Hence, wearing blue light glasses is an effective way to prevent your eyes from harmful blue light.
What do blue light glasses do? They are specially designed to filter out harmful blue-violent light rays that are commonly emitted from digital screens.
Which face types are suitable for rimless glasses?
Rimless glasses are mainly suitable for round faces, heart-shaped faces, square faces, and other most face shapes. Rimless frames are designed to be light, hence, they ease the wearer's stress, increasing comfort, and providing a wide view. Rimless glasses suit most face types, suitable for people who are short-sighted within 600 degrees. If the degrees are too high, you should not wear rimless glasses. When the degrees are too high, the lens will be suitable for thickening, so rimless glasses will show bloated.