Do You Know PC Lenses?
Eyes are the windows to the soul, the lenses are the life of a pair of glasses. Eyes nearsightedness can not be separated from the glasses. A pair of glasses can not be missing the composition of the lenses. But what we do not know is that there are many types of glasses lenses, not just the resin lenses that we know. So what are the materials of glasses lenses? Today we will introduce you to one of the eyeglass lenses: PC lenses.
Introduction
PC lenses originated in 1957 as a thermoplastic material called polycarbonate. This material is from space exploration, so PC lenses also call "space lenses" and "cosmic lenses". Because they are strong, unbreakable and impact resistant, so they also call “safety lenses”. They are the lightest material used for eyeglass lenses. In terms of performance, PC lenses are better than resin lenses.
History of Development
In 1957, GE (General Electric) was the first to develop a PC (polycarbonate) plastic, called Lexan. Bayer (Germany) followed with their PC plastic Makrolen.
In the 1960s, at the end of World War II, PPG converted the former military CR-39 resin material to civilian use for lenses.
In 1978, Gentex USA was the first to manufacture safety lenses from PC. Taking advantage of the military aerospace program.
Vision-Ease Lenses, Inc. was the first to introduce PC prescription lenses in 1985.
In 1991, Transitions (USA), launched the first generation of color changing resin lenses.
In 1995, polarized PC lenses were born.
The share of PC lenses in the U.S. market was 35%, while glass lenses accounted for less than 3% in 2002.
Advantages of PC Lenses
First of all, PC eyeglass lenses are light weight, 37% lighter than ordinary resin lenses for the same degree.
What's more, PC lenses have strong toughness not broken, and super wear-resistant, impact resistance is up to 12 times the ordinary resin. For professional sports glasses, frameless frames and other glasses with high requirements for toughness is very suitable.
Finally, PC material has 100% UV protection, within 3-5 years will not yellow. PC material can degrade recycling, is relatively environmentally friendly material.
Visit our website to see more PC glasses.
If you have time, you can read this passage to know the Glasses Maintenance Methods / Steps.
6 notes
·
View notes
A simple way to unlock your phone from its carrier network and find a cheaper phone deal.
Mobile Unlocked
0 notes
Cell phone: now I'm pissed...
I have had the same cell phone....3-4 years.
Finally make a claim cuz it randomly crashes/battery will lose stupid amounts of power.
....a few years ago, google tried (failed, and seemingly never tried again) to make a phone where...you could change pieces (battery, camera, cover, etc) to not only customize it, but upgrade it when available.
THAT WENT OUT THE FUCKING WINDOW!
My new phone has a PERMANENT battery.
NO. We already know mining for battery minerals is killing the earth, but let's make my phone a one hit it and quit it? So if it's bad/fails, the whole thing is TRASH!?
FUCK OUTTA HERE.
I always forget the term, but never the concept: Planned obsolescence.
LIMITED earth resources, but unlimited growth and greed.
GREAT FUCKING LOGIC!!!!
1 note
·
View note