Yes, I DO laugh at the "variant" listing of lense in an on-line dictionary.
Actual, real dictionaries list only one acepted spelling of the word, and that is lens. It's a FOUR-letter word for crying out loud...and it is lens. The word lens is spelled the same in American, Canadian, United Kingdom, and Australian dialects all over the world--no check/cheque, color/colour, center/centre variants. There is one,single proper spelling and it is "lens". Four letters. The word has never had a letter dropped, as was done in American spellings of words such as colour being shortened to color.
As skieur commented, many words are spelled incorrectly. A good example is ridiculous. There is no "e" in the word, and yet in on-line message fora, the word ridiculous is almost universally spelled rediculous. That does not make it the correct spelling. Same with lens...there's only one, single correct way to spell it. Again, if we went by online forum hacks, or sixth graders, we'd spell things incorrectly all the time and promote the mistakes to official dictionaries. That's a bad idea.
U-no wht I mean,rt? It's also "aperture". There is no "A" in the middle of the word aperture, and yet, on-line perhaps 75% of people spell it aperature, or appature, or aprature.
It's also amateur photography. Not amature, amerture, or ammature. The inclusion of "lense" as an accepted variant of lens is quite laughable.
How about this: I think it's rediculous how ammature photografers want to buy a new lense every time they get a few dollers saved up. Commonly misspelled word count in that sentence: five words,all wrong...