The lifetime of contact lens
Traditional type: the replacement cycle is more than 3 months, not more than 1 year, that is, we say we abandon after one season, and we can abandon after half a year and a year.
Frequent-change type: the replacement cycle is more than 2 weeks, not more than 3 months, that is, we often say that we throw them after 1 month or two weeks.
Abandoned type: as a one-time use, common for the day use.
Contact lenses, like food, have an expiration date. For example, the shelf life of daily contact lenses is one day (after it is opened), and can not exceed this time. And the life span of a pair of glasses depends on how long you use them each day. Although different lens materials determine different wear times, we recommend that soft lenses should not be worn for more than 8 hours per day (do not wear soft contact lenses to sleep). Traditional contact lenses can be used for a long time, so the lens is easy to produce protein-lipid deposition, and then they are easy to cause eye surface inflammation and hypoxia reaction. If conditions permit, it is recommended to choose the frequent-change type and discard type, the shorter the cycle, the healthier.
Why do glasses with the same prescription feel different?
The style of the frame has changed. The structure of the new glasses and the old glasses (half-frame, rimless, full-frame) may be different, and the angle of the glasses may also be different, which will cause visual differences and the symptoms of dizziness after wearing the new glasses. If you used to wear rimless glasses or half-rim glasses before and switch to full-frame glasses, you will feel that his field of view is limited and you will feel a little uncomfortable when you see the edge of the frame. If you wear full-frame glasses before, you will feel the edge of the lens when you change to half-rim glasses. It's too bright to adapt. There is another situation, changing from a frame with a nose pad to a frame without nose pads. Because the distance between the lens and the eye has changed, the position of the nose pad has also changed, which directly affects the relative position of the optical center and the pupil, as well as the distance from the back vertex of the lens to the cornea, which naturally affects the visual difference. In this case, you can fine-tune the nose pads, or after a short-term adaptation, you can generally return to normal.
Normally, opticians do not want to change their original visual habits (to maintain visual continuity) and want to copy a pair of glasses with the same vision. When optometry, they must provide the used old glasses and their optometry record sheet for inspection. With personnel reference. Simply put, comfort is equal to habit. If you want new glasses to wear comfortably, you must keep your original habits. It's not just the reproduction of luminosity. If you don't wear suitable glasses often, you will feel uncomfortable once you wear them.
In recent years, the glasses chain has developed fastly, especially in large and medium-sized cities. The professional glasses stores use their own technical force, progressive optometry equipment, and years of store reputation, which drives the whole industry to improve the quality of products. Nowadays, with the development and expansion of the eyewear industry, eyewear chain stores have become the main force of eyewear product sales in China and even the world. Moreover, tens of thousands of people are directly or indirectly engaged in the operation or management of eyewear chains or related to them. The eyewear industry provides us with a large market and benefits.
How do myopic glasses work?
The formation principle of myopia is that when the light from the outside world enters the eyeball, it is refracted by the eyeball's refractive system and cannot be accurately imprinted on the retina. The image is in front of the retina. If a concave lens is placed in front of the eye before the light enters the eye, it shifts the focus of the myopic eye from a point in front of the retina to the back, so that it lands directly on the surface of the retina. When parallel light passes through a concave lens, it diverges, meaning that it has already diverged once before entering the eye and then is refracted normally by the eye's refractive system. When the light is refracted through the eyeball, the distance of the image will be longer. So the distance of the image will be correspondingly pushed back compared to the non-divergent light. But it will just fall on the retina, and the image will be accurate in the right place.
Why are eyeglass frames are so expensive?
The industrial chain has factories, brand owners, regional general agents, retailers. Each link needs to share the risk and profit. They have high operating costs. In addition to the well-known rent, they have the costs of labor, decoration, and so on. There is another important reason. It is the inventory loss because of the style problems. This aspect of the cost must be amortized. From the structure and appearance design of the glasses frame, the development and application of raw materials, processing technology, to manufacturing equipment and procedures, the actual cost may be much higher.
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.
The sporty style
Sporty style frames are a little cool, full of vitality, well-designed. They pay attention to every detail, with publicity but not exaggerated feelings. With good material, they effectively prevent collision injury to your eyes in the process of movement, greatly improving safety. The style is simple and smooth, and the appearance is dynamic and fashionable, and the color collocation is diversified. With the integration of four progressive technology to better protect your eyes, they are your outdoor leisure tourism sports choice.
