How to buy prescription glasses online?
Go to the ophthalmology department of a regular hospital first, because you need to take a photo of your optometry sheet to the seller when buying glasses online. Accurate optometry is the first step in choosing the right glasses. After getting the prescription, we can choose the frames online. Various material frames have different properties. Some are light and some are tough. In short, each has its own characteristics. I can't say which one is better. According to your own needs and face shape, choose the suitable glasses frame. Next, choose lenses. There are mainly two types, spherical lens, and aspherical lens. The aspheric lens is better. Also, confirm what specific functions are needed, such as radiation protection, UV protection, etc. Finally, the seller will look at the data on the prescription. If your eyes have high astigmatism, you need to add money. Then take the payment and wait for your new glasses. It’s unbelievable that you can buy glasses online in just a few minutes. Buying eyeglasses online is fast and convenient.
Select qualified optical lenses.
Anti-blue light lens must be qualified optical lens first and must have a certain percentage of anti-blue light effect. The general anti-blue light optical lens effect is about 30%. Even if it is not nearsighted people, it is best to choose the brand lens of reliable optical lens production enterprises. Anti-blue light lens is only suitable for people who use electronic display devices such as computers for a long time and is not suitable for patients with visual fatigue symptoms.
Why does shape memory alloy have memory ability?
It starts with its microstructure. When a metal is solid, its atoms are always arranged in a regular way, forming a lattice. Under different conditions, such as temperature, metal may have a different structure, in which case it is said to be in a different phase. The change from one phase to another is called a phase transition. The properties of a metal change during a phase transition. The temperature at which a metal transforms is called the transition temperature. The difference between a shape memory alloy and other metals is that the phase transformation process in a shape memory alloy is reversible under certain conditions.
Who should wear blue light glasses?
Teenagers, middle-aged and old people need to wear blue light glasses. The lens of a teenager is clear, pure, and still developing. Their eyes are less resistant to blue light than adults and are more vulnerable to long-term exposure to blue light, which can promote the development of myopia. Teenagers study more nervous, are free to love to play computer games, love to watch TV programs. Blue light damage can be said to be everywhere. As a result, teenagers are among the biggest victims of blue light. Macular degeneration is a common disease in the elderly, usually occurring after the age of 45, and the incidence increases with age. Blue light can accelerate the progression of macular degeneration, especially in patients following cataract surgery. Blue-blocking glasses are still the best preventative measure.
Why are some glasses expensive and others cheap?
Lenses do not regulate vision, but some progressive lenses can help the ciliary muscles to adjust. The quality of the lens is mainly determined by the transmittance, the surface, the aspherical surface, the refractive index, the coating quality.
The higher the refractive index, the thinner the lens, and the more expensive the price, for some people with high degrees, the lenses also play an aesthetic role. Commonly used are green film, and some are purple film, gold film, etc. How much cheaper is a relative number, and there are many other factors to consider besides price.
Eyeglass Holder- Cat
It has a universal design for reading glasses for men, women, or children. It's easy to find your glasses in the room. The decorative bracket makes your glasses convenient. You can enjoy a lovely desk or bedside table spectacle frame specially designed to accommodate your reading glasses. The frame has a special slot in the nose that fits perfectly on the arm of your glasses. With this cute and convenient stand, you won't lose or misplace your readers -- it's easy to find on cluttered desks!
Half frame glasses
The half-frame glasses are more appropriate. A round face is wide on the left and right. For the half-frame, because it doesn't have a line underneath it, it will make the face look rectangular. Wearing the full-frame will make the jaw look narrower, and the jaw of a round face is narrow, so wearing the full-frame will make the jaw look narrower. Wearing a half-frame lengthens the jaw and makes up for the lack of a round face. On the other hand, full-frame glasses are more suitable for long faces.