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.
Reading Glasses by SCOJO New York, Original Gels Readers, Rimless Oval Glasses
They are high-end non-prescription reading glasses for women and men. They are well made and comfortable to wear. They use lightweight, ultra-durable TR-90 class plastic (a thermoplastic material that is flexible and can bend under pressure without breaking). The flexible lightweight glasses are for maximum comfort. Corrosion resistance, optical quality, there is no distortion. The acrylic lens, at any angle, has an extremely high definition.
Types of Bifocal Lenses
Executive: in this type of bifocal lens, the lens is separated completely from each other and the upper part of the lens and the lower part of the lens are divided into two equal halves. There is a distinction line and it is visible.
Progressive lens: these types of lenses are more popular than the other kind of lenses. There is no line in the progressive lens. There is a slow transition of the power from the upper part of the lens to the lower part of the lens.
Progressive multifocal lenses: a progressive multifocal lens gradually changes power from the upper part of the lens to the lower part of the lens and gives a smooth transition between the two different types of bifocal lenses. There is no distinction line in the lens. They are popular because they provide better adaption, comfort, and clarity than the other lenses.
The production process of titanium frames is complicated.
The production of titanium frames requires special processing equipment, special welding technology, and electroplating technology, which has many processing procedures and high production costs. In particular, some glasses choose the most difficult pure titanium andβtitanium. Titanium is very soft and very sticky, and very lively at high temperatures,so the processing is very difficult.
How to buy glasses that have quality assurance online?
First of all, you need to find a good eyewear online store and determine if there is any discount information. Big glasses usually have preferential information, and there are certain preferential activities. Lenses are very important to us, so the best quality is good. The price can be considered as the average level because low-level lenses are best not to prevent damage to our eyes. The frame is not that important, and it is only used to support the lens. Choose a pair of good-quality glasses for this combination. Optometry is closely related to the quality of the glasses. If it's not accurate, your glasses must be substandard. If your optometry data is good, you will get a real pair of glasses. You need to make sure your optometric data is accurate, which is a process you must go through when wearing glasses online.
Parameters of lens material selection
Abbe number
Since the refractive index of the lens material varies for the light of different wavelengths, and white light is made up of various colors of light of different wavelengths, the dispersion phenomenon occurs when the lens refracts white light. The dispersion coefficient is an important index to identify the sharpness of lens imaging, which is usually indicated by Abbe number (Abbe number = dispersion coefficient). The larger the Abbe number, the smaller the dispersion, and vice versa, the smaller the Abbe number, the larger the dispersion, and the worse the resolution of the image.
Impact resistance
Humans have been using glass lenses for about 300 years, and it was not until 1947 that the first resin lenses made of CR39 were produced. A big reason for using resin lenses is their safety, i.e. impact resistance. Only lenses that pass the Drop Ball Test are considered safe. Combining the above two parameters, we can compare different lenses.
5 Signs You Need Reading Glasses
In this section, we will list some signs you need reading glasses.
- You are over 40 years old. Everyone’s eyesight changes at a different rate, but most people develop presbyopia in their 40s. Presbyopia is a condition in which the eye strain to focus on nearby objects, which is different from farsightedness, a condition in which you can see distant objects clearly, but objects nearby may be blurry. Farsightedness is usually present at birth, but presbyopia develops during the aging process.
- If you find that you never seem to have enough light when reading, regardless of the room type or the number of lamps you have turned on, it may be time to get reading glasses. According to a study, a 60-year-old people requires three times as much light as a 20-year old to do the same task.
- If your eyes get tired when reading or working at your computer, you may need reading glasses. Do you find yourself dozing off at your computer, or do your eyelids get heavy when your reading or do detailed work? If so, you may be developing presbyopia, and you may need the reading glasses.
- Another sign you need reading glasses is that you are getting more headaches. Consistently straining your eyes to read or focus on craft could give more headaches. A headache right behind your eyes could be indicative of hyperopia. It is important to remember the 20-20-20 rule: every 20 minutes, look at something at least 20 feet away for 20 seconds. If your headaches persist, you should see an eye doctor and have a check.
- If you see halos, you may need reading glasses. When your lens cannot focus light into your retina, it makes your vision appear blurry. Thus, reading glasses can solve this problem.
Do I need reading glasses? After reading this post, you may have a basic understanding. If you need a pair of reading glasses, try Koalaeye glasses. They are stylish and cheap, and the glasses will be mailed to you with great convenience.
