How to buy contact lenses online?
Choose well-known brands.Nowadays, the contact lens brands in the market are mixed, with the proliferation of inferior products, but there are still some authoritative and well-known ones, like Johnson & Johnson, Bausch & Lomb, which are products recognized by most users, and you can rest assured to buy them.
Phone can identify polarized sunglasses.
Take a mobile phone with an LCD screen, turn it to maximum brightness, and look at the LCD screen through the lenses. Make sure the lenses are parallel to the display, and then slowly rotate the phone. When the true polarized lens is rotated at a certain angle, the light from the display becomes obviously darker, or even pitch-black. If they're not dark, they're not polarized sunglasses.
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.
Price positioning
In terms of positioning, it should conform to students' purchasing behavior, that is, the middle and low-grade products are mainly used, and the appearance requirements are stylish and novel. In addition, you can be properly supplemented with a small number of high-end products, because your market is not only the school but many residents around.
How do bifocal reading glasses work?
Bifocal reading glasses have two different lenses on the same lens. The top of the lens is your normal distance prescription, while the bottom is for close-up viewings, like reading. The two lenses allow you to alternate between them by moving your eyes up and down as needed. A bifocal lens is a type of lens that has two different areas of vision: one for close range and one for long-range. Typically, the upper section covers remote vision and the lower section covers reading. With a traditional bifocal lens, you can see the difference between the two lenses because the lower curve is a little different.
What are polarized lenses for?
Polarized lenses contain a layer of polarizing plates in which molecular chains form a light-grating structure in which dichromatic pigments, which absorb polarized light, are evenly distributed. A beam of light is absorbed when it vibrates in the same direction as the bars of the molecular chain of the polarized lens. The grating direction formed by the molecular chain of the polarizer is the axial direction of the polarizer, which is generally horizontal. When polarized lenses are worn, they absorb all the light that vibrates horizontally, thus absorbing the glare and preventing it from reaching the eyes.
Are Blue Light Glasses Bad for Your Eyes?
After learning some basic information about blue light blocking glasses, are blue light glasses bad for your eyes? No, the blue light glasses would not damage your eyes. Blue light blocking glasses can protect your eyes from harmful blue light and UV rays by using special lens technology to block and filter them out.
Sunlight contains the full spectrum of visible light including red, orange, yellow, blue, indigo and violent, and also non-visible light such as ultraviolet and infrared. A moderate amount of blue light and UV rays can be beneficial for us, but too much can damage our eyes.
