Haven't tried it, but I have some that my SIL gave me because she got it from her salon. I opted to not use it because there are some pretty gnarly potential side effects that I don't want to mess with (ie: possible permanent eye staining). I'd rather invest in some really good mascara or if you want to be more spendy, getting eyelash extensions that don't carry those risks.
If you plan on using it, I'd talk to your doctor first and make a good informed decision.