Question

lenses that always diverge light rays that strike them

is that convex or concave? I am not sure.

Answer 1

Since this is not my area of expertise, I searched Google under the key words "<I>convex concave lens</I>" to get these possible sources:

http://en.wikipedia.org/wiki/Lens_(optics)
http://www.lessonplanspage.com/ScienceConvexConcaveLenses69.htm
http://camillasenior.homestead.com/optics4.html

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.

I hope this helps. Thanks for asking.