About industrial pure titanium
For the industrial pure titanium, titanium content is not less than 98%, containing a small amount of oxygen, nitrogen, hydrogen, carbon, silicon, and iron impurities such as dense metal. The labels are TA1,TA2,TA3,TA4. It's arranged by more and more impurities. The TA1 titanium content is more than 99.5%, and the price is not high. But no matter which links, for molding, welding, polishing, processing difficulty is very great.The price of almost all titanium alloys in the national standard is higher than that of pure titanium.
In reality, the price of β titanium is higher than pure titanium. Pure titanium is almost no elastic, but β titanium is not only elastic, and has the advantages of ultra-light corrosion resistance. β titanium does not have a specific composition. Memory titanium can cost tens or even tens of times as much as pure titanium.
Using memory alloy to make glasses frame is the use of its superelastic characteristics at a certain temperature (elasticity is several times that of stainless steel) and did not use its memory function. Compared to beta-titanium, memory titanium is so difficult to process. It is so elastic that shaping is difficult and impossible at room temperature, and memory titanium heat treatment is another difficult and even secret process.
How To Choose Better Night Driving Glasses?
Driving at night has a high accident rate because of poor visibility, blinding headlights, and fatigue. Now the market exists a few main glasses: sunglasses polarizing lenses, Glasses that use or mimic the first generation of patented technology. So how do you compare the options between driving and wearing glasses?
Night driving lens is relatively special compared with daily driving lens, not only to prevent strong light and see the road more clearly. According to the national motor vehicle driver special glasses standards, QBT 2659-2004 daily light transmittance should be more than 8%, night light transmittance should be more than 75%. Be sure to consult customer service. Ask about the situation. Note that a pair of polarized sunglasses are not suitable for use at night, and the light transmittance must reach the national safety standards.
Wear glasses timely.
You must pay attention to that whether it is myopia, farsightedness, astigmatism, it is recommended to wear glasses in time. Especially for children, for the first time, it is recommended to have professional ophthalmic optometry. If it is pseudomyopia, temporarily they do not wear glasses. Drugs, physiotherapy, and other methods can be used to promote rehabilitation. If it is true myopia because the axis of the eye has increased, it should be corrected as early as possible, and then take comprehensive prevention and treatment measures to control the deepening of myopia. Otherwise, it will not only affect study life but can make myopia more and more serious.
How Do Bifocal Glasses Work?
After learning some basic information about bifocal lenses, you should know how the bifocal glasses work.
With a pair of bifocal glasses, it would be convenient since they combine all your vision needs into a pair of glasses and you do not need to switch two pairs of glasses frequently. Bifocal glasses are usually designed to for those people who are over the age of 40-45 that need additional help with their near vision due to the effects of presbyopia where the crystalline lens inside the eye naturally begins to lose its ability to focus on near objects.
If you work in the office, you may need a pair of bifocal glasses. The top distance vision in the top of the lens can be used for meetings or presentations and the near vision in the bottom of the lens can be used to look at the computer screen or at documents.
The price of prescription glasses
You need a current (unexpired) prescription to order glasses online. You will enter your prescription and select the available lens options during checkout. Prescription glasses start at about $40. Single vision lenses are free when you buy the frames, and progressive wireless lenses typically cost an extra $80 or so. Other lens options include clear lenses with no extra charge, basic tone lenses (for sun protection) with the price of $40,polarized-tone lenses (for protection and glare reduction)with the price of $50, and transition lenses (for indoor and outdoor use) with the price from $65.
How to use the eyeglasses holder straps?
Slide the plastic holder at each end of the string to the ends of the eyeglass arm. Some glasses retainers have pockets at the end of the line instead of plastic retainers.The pockets cling to the arms of the glasses. Tie the string around your head and put your glasses on. Have the rope tied around your neck and your glasses in front of you. If you want to take your glasses off for a while, hold them over your chest and release them so they can hang on the cord.
Find the right size
The right glasses should sit comfortably on the bridge of the nose, not pressed against the forehead or cheeks. But they don't stay at the tip of the nose for so long that they slip while squinting or wrinkling your nose. The fit of the nose determines the distance between the glasses and the face. A proper fit should allow the lens to be between 14 and 24 millimeters away from the eyes. When you want to find glasses that fit, don't clip, don't slip, and don't lead to discomfort, you have to find out the size you need.
