Why are rimless glasses so expensive?
Rimless glasses are the design vantage point in the frame of glasses. The structure of rimless glasses requires many higher physical features (flexibility, surface texture, etc.) and machining accuracy than TR, PEI, and other materials. In order to ensure comfortable wear, the common materials are very exquisite. And for processing technology, the frame is the most difficult. It's not just grinding, it's a full polishing, and it's perforating. This is the technical demand and the most time-consuming.
Wearing glasses correctly will not get deeper degrees
The development of myopia is not directly related to wearing glasses. Patients with myopia wear suitable glasses and pay attention to eye hygiene, and the degree of myopia will stabilize at a certain level. But if you think that with glasses, everything will be fine. If you don't pay attention to eye hygiene in normal times, if you continue to keep your eyes in a state of fatigue for a long time, it will lead to vision loss and deepening of myopia. In addition, wearing improper glasses such as no optometry or inaccurate optometry, too large power, will increase the burden on the eyes, reduce vision and deepen the power. For some people with high myopia (more than 600 degrees), although they insist on wearing glasses, the degree will still deepen, accompanied by changes in the fundus, which is medically called pathological myopia. This deepening of myopia is related to the degree of myopia and family and has nothing to do with wearing glasses.
Titanium alloys have low thermal elasticity
The thermal conductivity of titanium is about 1/4 of nickel, 1/5 of iron, 1/14 of aluminum, and the thermal conductivity of different titanium alloys is about 50% lower than that of titanium.
The elastic modulus of titanium alloy is about 1/2 that of steel, so its rigidity is poor and is easy to deform, and it is not suitable to make slender rods and thin wall parts. When cutting, the spring back of the processing surface is very large, about 2 ~ 3 times of stainless steel, resulting in severe friction, adhesion, and bonding wear of the knife surface.
What Are Bifocal Glasses?
Bifocal lenses are divided into two parts to accommodate two different prescriptions in one lens. One area of the lens will have one prescription (usually distance) and a segment in the lower half will have the other (usually near vision).
Bifocal glasses are most used to correct presbyopia - an age-related eye condition where the eyes begin to struggle to focus on anything up close. This difficulty usually results in people requiring glasses with two different prescriptions, one for short and one for long-distance.
On bifocal glasses, there is a distinct line between the different prescriptions. Wearers have to look up and down to switch between the prescriptions they need, with long-distance prescriptions at the top and near vision at the bottom.
Sports goggles
With the improvement of people's sports concept and sports protection concept, sports goggles are also widely welcomed. Safety glasses are worn during sports must have four major functions, safety (PC lenses), protection (TR-90 frame, soft and flexible), comfortable (non-slip nose pads and foot covers), and beauty (match sports and leisure clothing).
Sports goggles with shatter-resistant plastic lenses and side shields can prevent balls or sand from hitting the eyes. It can be fixed on the head without worrying about falling off during intense movements. The unique design of the rim of the frame makes the glasses very close to the human face and has a proper external isolation effect so that the human eye is not easy to be attacked by bacteria. The special lens has the functions of anti-fog, anti-shock, and ultraviolet rays, which is very suitable for outdoor activities.
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.
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.
