What are bifocals?
A bifocal lens is a lens with two focal points. Because of the imaging principle of the lens, even half of the lens can still present a complete image, and the two images do not interfere with each other. In the past, both short-sighted glasses and presbyopia glasses were called single-focal lenses, which had only one focus. Later it developed to the bifocal lens, and the same lens is divided into upper and lower two parts. The upper part of that lens is used when seeing far, and you look down when seeing close objects, just the reading distance, naturally used the second half.
Glasses should not have serious color differences.
Children's eyes are not fully developed, and the eyeball is still growing slowly, at this time it is best not to wear such blue light glasses with the serious color difference. If you always see things with color differences, it will cause eye discomfort, resulting in increased myopia, but the opposite. The big color difference will cause low light transmittance, affecting child macula development. In the case of long-term distortion and discoloration, visual physiology and psychology will be affected.
Blue light glasses for children have special lenses that block some light waves, which may help protect children's growing eyes from digital eye strain. Blue light lenses sometimes have a slight yellow tint. You can buy prescription or non-prescription glasses with child-size frames and lenses that filter blue light. They don't filter out all the blue light, but they can reduce your child's exposure to blue-violet light by 80 percent or more.
Reading Glasses
At present, there are two prescriptions for reading glasses. One is to adjust the power of glasses with clear objects at close range, plus 1/3 of the power for adjustment. The other is to use low power that can see close objects clearly. The practice of many elderly people has proved that the latter one is better between two methods.
What are the colors of the fishing polarizer?
Amber, yellow, or orange lenses are very suitable for wearing on cloudy days. They can have a very clear vision, but they are not suitable for use on sunny days. Gray or dark green lenses can maintain the most natural original color when viewing objects, which is a good choice. Sunglasses are not only required to be worn in summer but they must also be used throughout the year. Wear it on sunny days and also on cloudy days. Don't think that the sun is not strong on cloudy days and the weather is not hot, so you don't need to wear sunglasses. The harmful ultraviolet rays will harm your eyes unknowingly. Therefore, even if it is a cloudy day with thin clouds, you must still wear sunglasses to protect your eyes.
Suggestions for Using Varifocal Glasses
If it is difficult for you to get used to the new varifocal glasses, here are some suggestions for you.
1. Wear the varifocal glasses consistently so as to let your brain learn how to use them.
2. The most common accident is tripping when getting used to new varifocal glasses. So, you can mix up your routine to keep your brain active and prevent you from tripping up.
You can also ask those who wear varifocal glasses to give you some advice.
Why Are My Progressive Lenses Blurry?
Progressive lenses are optical lenses designed for simultaneous correction of far, medium and near. Progressive lenses use polishing technology to achieve a gradual transition between the two focal lengths. With progressive lenses, people do not have to switch their glasses for different purposes.
However, with the usage of progressive lenses, there are some problems of progressive voices. One of the most commonly reported side effects of progressive lenses is blurry or fuzzy peripheral vision. The blurriness is usually most noticeable through the lower portion of the lens and to the left and right of near and immediate zones.
The Types of Blue Light Glasses
Computer Glasses - Clear Lenses
First, we will show you the computer glasses which have clear lenses, These glasses are made to be used when working on your computer, smartphone or while watching TV. The best computer glasses can filter 5-30% of all blue light.
Night Driving Glasses - Yellow Lenses
When driving at night, the blue light glasses with yellow lenses would be suitable. These blue light lenses are good at removing more of the highest energy blue light, around 440 nm and they are also able to distinguish traffic lights when driving at night. These glasses can block around 65-70% of blue light.
Blue Light Glasses for Sleeping - Red Lenses
The blue light glasses for sleeping have red lenses. The best blue light glasses come with red lenses and they block 99.5%-99.9% of all blue light and a large amount of the green light spectrum, from 495-550 nm.
After knowing the different types of blue light glasses, we will show you how to perform the blue light glasses tests.
