Just for your info, though, I did look it up. I have always trusted Mr. Webster. But he is a bit old, and he had it as "lense." That's why our family needs to invest in updated versions of the dictionary OR just google any word in question. Which I did, and here are the results:
Lense - 2.3 million refs
Lens - 54.9 million refs
"lense" is an accepted variant and perhaps more widely used among those who speak the Queen's English.
and from Princeton:
S: (n) lens, lense, lens system (a transparent optical device used to converge or diverge transmitted light and to form images)
The archaic spelling lense is sometimes seen, but Merriam-Webster's medical dictionary is the only major dictionary that considers this to be correct.
So, that's enough. I'm not really stupid or crazy. Just archaic - and I'm working on that. Just in case you wondered.