The Cons of Progressive Lenses
In this section, we will show you the cons of progressive lenses. There are some problems with progressive lenses especially when walking up and downstairs. Since the reading correction is at the bottom, the stairs may appear closer than they actually are. But this problem can disappear if you have adapted to them.
In addition, all measurements must be exact when creating a pair of progressive glasses. The optical center of the lenses must be placed exactly in front of your pupils in order to the lenses to work correctly.
Also, some people may find that it is difficult to adapt the progressive lenses, and it may take a few days to adapt them.
These are the progressive glasses’ pros and cons. If you want to a pair of progressive glasses, Koalaeye glasses are recommended. Koalaeye glasses are stylish and come at a cheap price. Besides progressive glasses, Koalaeye Optical also provides other eyeglasses, such as blue light block glasses, polarized glasses, sunglasses, and so on. So, if you need a pair of progressive glasses, try Koalaeye glasses.
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.
Why should children wear blue-light-blocking glasses?
Due to the short wavelength of blue light, the focus will fall in the front of the retina. In order to see clearly, the eyeball will be in a state of tension for a long time, causing visual fatigue. Studies have found that exposure to blue light at certain doses can damage epithelial cells on the surface of the eye, causing or aggravating dry eye. Harmful blue light has extremely high energy and can penetrate the lens directly to the retina, leading to the atrophy and death of retinal pigment epithelial cells. The death of light-sensitive cells will lead to vision loss.
Parameters of lens material selection
Abbe number
Since the refractive index of the lens material varies for the light of different wavelengths, and white light is made up of various colors of light of different wavelengths, the dispersion phenomenon occurs when the lens refracts white light. The dispersion coefficient is an important index to identify the sharpness of lens imaging, which is usually indicated by Abbe number (Abbe number = dispersion coefficient). The larger the Abbe number, the smaller the dispersion, and vice versa, the smaller the Abbe number, the larger the dispersion, and the worse the resolution of the image.
Impact resistance
Humans have been using glass lenses for about 300 years, and it was not until 1947 that the first resin lenses made of CR39 were produced. A big reason for using resin lenses is their safety, i.e. impact resistance. Only lenses that pass the Drop Ball Test are considered safe. Combining the above two parameters, we can compare different lenses.
How to Choose Reading Glasses?
If you need reading glasses when using a computer, you may want to choose a lower reading glasses power. This is because most people view their screen from a greater distance from their eyes than when they are reading a book or a magazine.
However, if you need reading glasses for looking at something very close or very small, you may need a pair of stronger power glasses.
In most cases, when two reading glasses’ powers seem equally suitable, choose the glasses with the lower power. Picking reading glasses that are too string typically will cause more discomfort problems than reading glasses that are a little too weak.
Benefits of glasses with nose pads
Glasses with nose pads reduce the load on the bridge of the nose and make them more comfortable to wear. In addition, glasses with nose pads can have a non-slip effect, especially for people with a low nose bridge. It will be much more comfortable to choose glasses with nose pads, so there is no need to worry about the trouble of holding the glasses all the time.
Metal square frame eyeglasses
A large square frame shows a face small, with a strong stylish sense. A lot of stars often use it for concave modeling, making their whole collocation more tide. People with diopters try to avoid choosing such large frames as daily optical glasses to wear.
