glass vs. acrylic lens

I know that lens usually come in two types, glass and acrylic. Acrylic lenses are easily damaged, while glass lenses are relatively scratch-resistant. In terms of performance, are there any differences in which the lenses affect the beam.

Are certain lenses more suitable for certain lasers?

For example, does Wicked use glass or acrylic lenses? How about those generic red laser pointers?

Oh, and is there a way to tell whether a lens is glass or acrylic without taking apart the laser?

if you use a lense made out of kryptonite, you can make a laser beam that weakens superman. or gives you his powers, if you accidentally put the batteries in the wrong way.

....ok i'll stop being silly now, i know nothing about lenses really, i believe it's been said glass ones are better for the beam though.

As an astronomer I wouldn't dream of using an acrylic lens (not that they make them) glass does not distort light like acrylic so stick with glass

I hear that acrylic lens are good for focusing down to a fine point, and glass are good for porjecting a dot over a long distance.

There's no real difference in performance in this application.

It is very cheap and easy to make an aspheric lens out of acrylic. Aspheric glass lenses are much more difficult to make so they are about 20 times more expensive. These are typically used for collimating light out of a fiber or diode and it is just way cheaper to do it with acrylic.

check out this thread, I found this site with lenses for just $.99 and prisms.
http://www.laserpointerforums.com/forums/YaBB.pl?num=1191904938

I have found that on the inside of the lens cap I fabricated, using a plastic/acrilic lens, after a week or two of using, that a filmy cloudy dot appears where the beam passes through... I just take it off and clean it.
Where-as the glass lenses I have in a few other caps with different focal lengths will not produce a cloudy spot on the inside of the lens...as well as the fact stated above, that plastic lenses distort the light morse-so than a glass lens
I prefer the plastic lens I have, because it has a great focal distance, for my liking, where to find a glass lens of the same fd would be more $ then I'd care at the moment to spend on a single tiny peice of glass