Choose a good merchant.
The best option is to return the goods with a quality guarantee.High-quality pure titanium frame production cost is not less than 100 yuan, and online sales will be not less than 50%, so you have to be careful with prices less than 200 yuan. Because pure titanium frame material cost determines its price, the ultra-low price of pure titanium frame is definitely not real.
The advantages are not the same.
The cellulose acetate frame is acetate plastic, belonging to a kind of thermoplastic material, and it is a material for nearly 20 years. It is widely used in the glasses industry material. Now with the progress of processing technology, it can be divided into plate and injection molding. The acrylic frame of the propionic acid fiber belongs to a kind of thermoplastic material. The appearance is transparent. The main feature is that the material density is high. They are hard to burn and are not easy to change color, with Impact resistance. It has softness, dimensional stability, and good processing formability. Many high-grade plate glasses are based on these high-quality plates, so the quality is more reliable. It is designed for a large number of people and the pursuit of quality of life students, especially for women.
Basic principles of progressive lenses
The surface of the progressive slice is divided into five regions. There are far, middle, and near optical areas. They are respectively corresponding to see distant objects, middle distance objects in the near distance objects. One pair of glasses is multi-purpose. In appearance, it is not very different from regular lenses. There is no clear dividing line. Distal use area: The area above the progressive slice is the distal use area, which is used to correct the distal refractive error. Proximity area: from the matching lens cross down, the refractive power of the lens continuously increases the positive degree, which is used to see close objects. Gradient area: The channel connecting the far and near areas. It is an area of regular change from top to bottom, used for transitioning and seeing objects at intermediate distances. The length of the gradient is very important for the wearer's adaptation. The rate at which the degree of gradient changes is called gradient. The gradient can be uniform or variable. Peripheral area: Changes in the surface curvature of the lens will lead to aberrations in the peripheral areas on both sides of the lens, mainly astigmatism and prism effect, which will interfere with a vision to a certain extent, resulting in blurred vision or distortion. And it will affect the wearer's adaptation to the progressive lens.
Glasses donation is also a form of recycling.
The old glasses were donated, and the love glasses were favored and recognized by the public. It is mainly aimed at orphans, left-behind children, single-parent families, and adolescents with mental retardation in poor mountainous areas. It lets the children who can not afford glasses really feel the care and warmth brought by people from all walks of life. Encourage them to take good care of their eyesight, study happily and grow healthily. And it can enhance the self-health care consciousness of young students.
Disadvantages of Prism Glasses
Although prism glasses are mostly used for correcting binocular vision, they also have some disadvantages which are said by those who have worn them. They said they suffer from some discomforts, such as headaches, pain with eye movement, wandering eyes. Misaligned eyes, nausea, double vision, and more. In most cases, side effects can be corrected with an adjustment to someone’s lens prescription, eyeglasses frames or medication.
At the same time, you need to know that alignment is extremely important when wearing prism lenses. Prism lenses may be not efficient if they are misaligned. But they can be fixed with a professional adjustment. If you are experiencing any problems with new glasses or your old prism lenses stop working, contact your vision optometrist.
Pay attention to the purchase of driving glasses.
A few points need to be kept in mind to avoid the risk of accidents. The frame should not exceed the size, because the researchers say the lens color should be gray or brown, so you can choose the aviator sunglasses, compared to other series. Aviator Sunglasses are always classic. There are plenty of cool experimental design glasses to choose from every year on the market. The selection of polarizing mirrors can filter the scattered light in the beam, remove stray light so that the light can be reflected into the eye from the right direction of the optical axis. The field of vision is clear natural. Light is adjusted in the same direction as light and reflects into the room, so the natural scenery looks soft and not dazzling, especially when driving a car or doing outdoor activities. It will affect the judgment of the object and cause danger, what’s more, long-term direct stimulation by the sun will lead to the decline of vision, the formation of myopia, hyperopia, astigmatism, or cataract.
Do blue light blocking glasses work?
Usually, blue light blocking glasses are yellowish, and this obvious color shift can cause serious visual fatigue. The aggravation of visual fatigue will not control myopia and will accelerate the progression of myopia. The most important thing is that some parents have the misconception that blue light blocking glasses can control myopia. If they allow children to use electronic products without guidance and control, myopia will definitely progress. During online classes, the best way to avoid the blue light damage of electronic products should be to relax their eyes between two classes. You can learn from the 20-20-20 rule recommended by the American Academy of Ophthalmology, which is to look at objects 20 feet away for at least 20 seconds for every 20 minutes. Also, you can take a break of 10-15 minutes between each online class. You can choose to look at the distance, play table tennis at home, or have fun with parent-child interaction. In this way, the tense shoulder and back muscles can be relaxed while the eyes are relaxed and rested. Not only can it prevent and control myopia, but it is also very helpful for improving the efficiency of learning. Teach children to blink their eyes more consciously when watching the electronic screen, and use a warm wet towel to heat the eyes during rest. A humidifier can be used at home to increase the humidity of the surrounding environment. This can effectively prevent dry eyes caused by looking at the electronic screens for a long time.