What kind of lens is a progressive lens?
Progressive lenses are optical lenses designed for simultaneous correction of far, medium (for computer use), and near (for reading). They are Progressive Additional Lenses (PAL). The so-called progressive, The so-called progressive, is the use of polishing technology to achieve a gradual transition between the two focal lengths. The advantage of this design is that the wearer can see far and near objects alternately without taking off the glasses.
What Are the Advantages of Progressive Lenses?
We have shown what the progressive lenses are in the above part. Do you know what the advantages of progressive lenses are？.
1. Only need a pair of eyeglasses. As mentioned in the above section, with progressive lenses, you just need a pair of eyeglasses and there is no need for you to change different glasses constantly.
2. No unsightly bifocal line. Progressive lenses come with the multifocal lens without a multifocal line. And there is a smooth shift in lens strength, you don’t have to deal with any sudden changes in clarity.
3. More comfortable. Due to no visible line, you might feel more comfortable with a progressive lens.
Sales points of note for color changing lens
The discoloration rate of the lens is related to the intensity of ultraviolet light. The stronger the ultraviolet light is, the faster the discoloration rate will be, while the vice versa. The degree of discoloration is related to the ambient temperature. The higher the temperature is, the color of the lens is slightly lighter. Otherwise, the color is slightly darker. With the progress of manufacturing technology, the discoloration rate, especially the fading rate of the discoloration lens has been greatly improved, and the interference of temperature on the color depth is becoming less and less. Either glass or resin lenses react only with ultraviolet light, not visible light, so in some environments, they do not darken.
How Should Glasses Fit?
In order to enable the glasses to fit on your face and ears, you need to pick the right frame width for your face. The width of your frame is the entire horizontal measurement of the front of your frames. A correct frame width will ensure your eyes are properly aligned in the center of your lenses for optimal vision. The frame width should be slightly wider than your face but with the space between your temple and frame no larger than a finger’s width.
Moreover, you also should ensure the Arm Length is right for you. The arms of glasses should run along with your temple and wraps around your ears. The arms should run horizontally and sit comfortably around your ears only touching your head right before your ears. Of course, you can find the arms-length of glasses on the side of the temple.
Why do you need blue-light-blocking glasses?
High-energy blue light would penetrate the lens and directly enter the retina, causing the atrophy and even death of retinal pigment epithelial cells. The death of light-sensitive cells will lead to vision loss or even complete loss, which is irreversible. Blue light at 415 nanometers to 455 nanometers is short, that is, high energy and harmful blue light. This band of blue light would penetrate the lens directly to the center of the macula, causing irreversible damage to the macula. Excessive intake of high-energy blue light would cause confusion of our biological clock, so the damage of blue light should be paid enough attention to.
How to Know If You Need Bifocal Glasses?
As you get older, you will find that is more and more difficult to read or focus on things that are really close up. This is called presbyopia and it is a common eye condition among older people.
How to know if you need bifocal glasses? If you find yourself squinting at the text that once was easy to read or your vision is blurry, you may need to see an eye doctor. In this situation, you may need bifocal glasses to correct your eyes.
If you currently wear glasses but see print more clearly when you remove them, it is a sign that you may need bifocal glasses in the future.
To know if you need bifocal glasses exactly, check your eyes by an optometrist or ophthalmologist.
Does it matter if the glasses are damaged when mailing?
Many people think that the frame of glasses is slightly damaged and can be ignored, in their eyes, if the lens is fine, the glasses are OK to use. In the whole process of matching glasses, it is necessary to choose a regular lens organization. The lens should be suitable, and the choice of the frame is very particular. Once the frame is out of shape, it needs to be replaced, and if left unchecked, further damage to the eye is possible.