Evolution of photochromic lenses
Thirty years after Corning invented color-changing glass lenses, another company has carried forward the color-changing glass lenses --Transitions Optical. In 1991, it became the first company to commercially manufacture resin color-changing lenses. Since its inception, the company has been a joint venture between PPG Industries (51%) and Essilor (49%). In April 2014, Essilor acquired a 51% stake in PPG. At present, the mainstream is resin photochromic lenses.
Which is better, MR7 lens or MR8 lens?
The refractive index of MR7 is 1.67, and its Abbe number is 32, so it has a good dyeing property. MR8 has a refractive index of 1.60 and an Abbe number of 40 or more. MR8 has stronger toughness, so it is more tensile and is not easy to break when confronted with strong impact. The lenses of MR7 and MR8 are different in the degree of heat resistance, and the heat resistance of MR7 is slightly weaker. MR7 is recommended if you want thinner and lighter lenses, but MR8 is recommended if you want higher light transmittance.
What Do the Numbers on Glasses Mean?
In this section, we will show you the glasses numbers meaning. These numbers on glasses frames are the measurements that indicate and describe the size of your eyeglasses frames, specifically:
- The eye size number (it is the size of the lenses on your frame).
- The bridge size number (the distance between the lenses).
- The temple length number (it is the size of that part of your eyeglasses frame, which rests upon your ears).
The three numbers mentioned above are the key measurements that describe the glasses measurements of the frames in eyeglasses. For example, you will see three numbers like 51-17-145 at the temple of your glasses. These numbers help the optician to choose the best-fitted frame for your head size and facial features.
All of these three numbers are measured in millimeters. These variations in frame numbers are fitted by a skilled optician so that it should be best fitted, be comfortable and look good on the appearance.
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.
The glasses slid up your nose.
Although glasses often slide up your nose and pushing them up can be annoying, it's easy to pull them tight. If your nose frame is metal, use your thumb to shrink the nose pad until the frame no longer slides. If you have plastic frames, soak the arm in warm water for 30-60 seconds, then apply slight downward pressure to the end of the arm. This will make it fit more behind the ears, which will tighten the overall fit and prevent slippage. If tightening the frame doesn't work, try using eyeglass wax to stop it from slipping.
Brick-and-mortar stores have fewer customers.
Brick-and-mortar stores are known to have a significantly smaller customer base, targeting a particular county or even a particular region and population. Mainly aimed at young students.For physical stores, their income range is relatively narrow. Therefore, in order to make more money, every physical store can only make a profit by raising the single sale price. Online stores attract consumer demand from all over the country and the world through the Internet.
Who are TR90 glasses for?
Both plate glasses and TR90 frames have their own characteristics and benefits. The plate glasses deduce fashion and are easier to match clothes. It integrates the plate and the texture of the metal, which can better reflect the personality and style. TR90 frames have been widely used in many optical fields like sunglasses, 3D glasses, polarized glasses, radiation-resistant glasses, etc.TR90 frame is so popular in men and women because of its variability. TR90 frame can be perfectly combined with other metals. The neat lines and bright colors bring fresh and energetic outdoor energy to the dull city. The light texture, about half lighter than the plate frame, can reduce the burden on the bridge of the nose, ears, and facial skin, which is very suitable for teenagers who just wear glasses.
