I agree with the school learning thing, internet forums have taught me most of what I know. Or at least, what I remember!
A disk drive lens would not work, unfortunately. Aside from the fact that they usually have filters in them that are optimized for specific wavelengths of light, the aperture is not large enough for most microdisplays.
You can buy suitable lenses for pretty cheap, it is not like they are rare or exotic. Just wanted to make clear that it was definitely not something a person could make on their own out of eyeglasses and water.
"Don't stop, believin! Hold on to that feeeEEEeeeEEeelin!"