The lenses used for correcting vision aren’t formed the same way used as lenses used in microscopes or telescopses, generally they all have one convex side and one concave side, as opposed to being convex or concave on both sides, so really you’d just be using the glasses in a different rotation.[/quote]
Actually DooM is right here. The reason that lenses in glasses appear to have one concave and one convex side is because we stick just normal old glass (which doesn’t change the focal point at all) onto the sides of the actual “lens” in the glasses to make them more aesthetically pleasing and to standardize the way that the glasses hold the lens so pretty much any frame can hold any lens. This hsould be a pretty easy fix, I’ll look into getting a PR up later today.[/quote]
On that note, then, a friend of mine mentioned the existence of little fresnel lenses camping stores and such sell that can be used for the purpose of solar firestarting, would be neat to have the assorted survival items be joined by a less jerry-rigged version of lens-firestarting that’s got the relative downside of not being useful for anything else. Not sure if he ws just full of crap, though.
