Brick-and-mortar stores have fewer customers.
Brick-and-mortar stores are known to have a significantly smaller customer base, targeting a particular county or even a particular region and population. Mainly aimed at young students.For physical stores, their income range is relatively narrow. Therefore, in order to make more money, every physical store can only make a profit by raising the single sale price. Online stores attract consumer demand from all over the country and the world through the Internet.
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.
Large round-frame glasses
Big round-frame glasses have large lenses, very dark frames. When you put it on, it makes you look good. Scientific design, let wear natural and comfortable, and you won't have a heavy feeling, with no pressure. When you wear a round frame, there is a kind of retro feeling. Round-frame glasses have an advantage, that is, they can modify the face line, looking small and shapely.
Disadvantages of progressive lenses
Wearing progressive multifocal glasses for the first time may cause slight dizziness and shaking when walking. Be careful when moving up the stairs. The perception of space changes, the perception of the distance of the object, and the perception of depth have changed. New wearers should not drive immediately and do vigorous exercise. When you look close, you need to turn your eyes down, and your eyes are mildly uncomfortable. Seeing the object through the blurred vision area around the lens, the object becomes blurred. Therefore, when new wearers look at things, turn their heads more, turn their eyes less, try to use the far-distance zone, the near-distance zone, and the middle-distance zone to see the object.
What Are Progressive Lenses?
Your eyes change with your age. When your reach your 40s, you may find that it is difficult for you to focus between a book, a website on a computer screen and the conference room whiteboard. Progressive lenses are growing in popularity among people who need help seeing near, far and in-between.
Progressive lenses have grown in popularity and are one of the most common solutions to treat vision loss that occurs with age or presbyopia. Progressive lenses have a seamless increase in magnification from the top to the bottom of the lens, helping you see clearly at all distances with just one pair of glasses. The top portion of the lens enables you to see the far-away objects, the middle portion of the lens enables you to focus on the intermediate objects and the bottom to see objects close-up. The prescription changes little by little across the lens surface providing a gentle transition.
After knowing what the progressive lenses are, do you know what are the pros and cons of progressive lenses? If not, keep on your reading and we will show you some information.
Choose the frame according to the hairstyle
If there are bangs, the upper edge of the frame should avoid contact with hair. If it is curly hair, it should be noted that the frame should not be too large so that the frame edge contacts the hair.
What Glasses Are Made Of?
In general, most glasses are made of plastic lenses. Why are glasses lenses made of plastic? In fact, plastic glasses are lighter than traditional glasses lenses used in eyeglasses, which means they are more comfortable to wear. At the same time, it is easy to apply lens coatings like anti-reflective to plastic lenses.
Besides, children’s glasses are also made of plastic because it is more resistant to impact. There are four main types of plastics used to make eyeglasses and sunglasses lenses which are plastic, Trivex, polycarbonate and high-index plastics.
The plastic lenses made from CR-39 were first introduced. CR-39 is an abbreviation for Columbia Resin #39, the 39th plastic of that type made by Columbia Resin.
Then the polycarbonate glasses were invented. Polycarbonate became out of this world once it found use in aeronautics. Polycarbonate is a type of plastic that can be produced as transparent and easily shaped, making it great for glasses lenses. Polycarbonate is impact resistant so that they are a good lens choice for kids. And the polycarbonate lenses have 100% UV protection.
Next, high-index lenses are available. High-index lenses have a high refractive index with a thin lens. Although high-index lenses are thinner, they are heavier due to the higher density of these plastics.
So, what glasses are made of? Most glasses are made of plastics. Then how are glasses made? To get the answer, keep on your reading.
