What is this on the back of my lens?

[rowghani]

Let me know as soon as you can. Posting it on ebay.

Thanks.

 

[Xmas]

Try cotton waste or qtip damp with water on a individual spot don't rub just dab then wipe any residue with dry cotton gently should disappear - spend time don't try to treat the whole surface at once.

 

[rowghani]

Hey man so it's not fungus or haze that I keep hearing about? Used a lens cleaner but wouldn't come off.