What are the characteristics of a titanium frame?
The so-called pure titanium, titanium refers to the purity of more than 99% of the titanium metal materials. To tell if a pair of glasses frame is pure titanium, we look at its purity. Because of the high melting point of titanium, lightweight, strong corrosion-resistance, used for the frame, they can wear for a long time, and will not let the bridge of the nose have a sense of pressure. But its disadvantage is that the material is soft, and only the relatively rough frame lines are made to ensure the stability and strength of the frame. Titanium frame has the advantages of corrosion resistance, acid and alkali resistance, high stability, good elasticity, good toughness, not easy to deform and fade. General glasses frame contains copper, so when we wear for a long time .it will produce verdigris, namely, copper sulfate. It is a toxic substance and is harmful to the human body. Because pure titanium tends to be soft, copper has to be added to make the frames more stable, which is why the frames have to be replaced over time.
Is it safe to buy contact lenses online?
Today's optometry is not a simple measurement of your degree. Through some professional instruments, they check the health of your eyes to see the health of your eyes. Is it appropriate to wear contact lenses at present? If there is inflammation in the eyes, it is forbidden to wear contact lenses, and if you wear them, it will cause harm to the eyes. If you buy online, you can't enjoy professional eye examination, try on, test, and other professional inspection and matching services that you can enjoy in professional stores, nor can you enjoy professional wearing and nursing guidance from professional staff. People often overlook eye problems that may result from the wrong choice of contact lenses, which are often overlooked by consumers.
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.
How do you buy prescription glasses on GlassesUSA?
Fill out a form on their website to enter a prescription, choose to have them follow up and require it later, or use their prescription scanner app on an existing pair of glasses. However, the app isn't always easy to use. You'll need your phone, a computer with enabled cookies, your glasses, and a magnetic stripe card to determine the size.
Design principle of aspheric lens
Early optical lenses use spherical lenses. Because the glasses were small round frames, the problem of lens edge aberration was not paid attention to. It wasn't until large frames became popular that the problem became apparent. For the spherical lenses, aberration cannot be corrected with the combined lens. Only a few variables of the lens can be found to reduce aberration and improve clarity. Aspheric lenses are designed to reduce the aberration of optical correction lenses and to make lenses flatter and reduce lens magnification. We can get clearer, thinner, lighter-quality lenses. Thus, aspheric lenses are used to reduce aberration and astigmatism to a minimum, close to the natural vision of the naked eye. The spherical aberration can be reduced by changing the curvature of the edge. The refraction in the central region is high and decreases evenly toward the edges.
Tortoiseshell glasses have many benefits.
Tortoiseshell glasses are made from the only sea turtle on the earth that can digest the glass material, and its sea turtle is the country's most precious wildlife, which is of great value. Wearing tortoiseshell glasses will not easily slip off even if you sweat and will not produce allergic symptoms. Tortoiseshell is so strong that it will not break even when the frames are bent to 45 degrees and will not be deformed throughout the year. In addition, the stability of the tortoiseshell is good.
Driving Glasses - ROCKYOU
Rockyou brand was founded in 2014, with the company adhering to the quality is life concept. With advanced equipment, professional team, and perfect management system, in line with the reputation, quality, service, efficient purpose, the company has gradually grown into a brand of excellence in this rapid economic tide.
