I have used this product for quite a while, mostly for its cooling properties whilst using a VDU.
When you use it the rollerball may be dry, which means it can catch crepey and mature skin so you must roll it on your hand abit just to activate the solution to lubricate the rollerball to stop the ball from catching any skin in it.
my problem with the rollerball was that as a major makeup wearer I was worried that I was contaminating the solution with all the makeup from my face
(concealer, foundation, powder -ya know!)
I was sooo glad when I found out that they were coming out with a tinted version as the formula is already coloured, It is available in just 2 colours I am the lightest (Im a mac nc25) but I still wish they did a 3rd much darker colour as the current dark colour only goes upto a mac nc40-ish.
I definitely recommend the clear one as a carry around for anyone male or female who works awkward shifts, or has long working days, little sleep or works with a VDU. DEFINITELY SUITABLE FOR MEN even if its only for the cooling properties, the product and packaging is unisex.
I cant comment about whether it lightens dark circles as I usually use this product in conjunction with other products and I have a tendency to rotate my products