Why Are Glasses Useful. Glass is useful for the formation of lenses (used to magnify or demagnify light) and it is also useful for containing something without blocking light passage into/out of that container. Why you might need computer glasses.
Can Wearing Glasses Improve Your Vision? Reading glasses are intended for occasional use, and while wearing reading glasses won't permanently damage your eyes, an eye doctor can provide. If you wear glasses I've got some good news: you may well be smarter than the average person.
I have a Tyranitar, and I don't know what item to put on it?
This technology already exists in the form of AR glasses.
The main reasons are that glass lenses are heavier, more delicate, and more difficult to produce. Even proto-sunglasses, that predate corrective lenses, weren't made from glass. The fact that they are actually worn on your face, and thus are conspicuously visible to all those with whom you interact, means that your glasses are arguably the single most important item in your wardrobe.