"Most eye creams do very little other than moisturise the skin's surface and therefore temporarily plump up fine lines and wrinkles due to their hydration effects," she told R29, and it pays to know your stuff. "One thing that a lot of people don't know is that eye 'bags' or puffiness is in fact different to dark circles or shadows underneath the eye," Dr Mahto continued. "Dark circles have a number of causes, but using brightening agents around the eye such as vitamin C , as well as peptides and caffeine may help to a limited degree. If, however, the dark circles are due to a loss of facial fat underneath the eye, then no amount of topical eye cream will reduce the appearance of the shadow which may develop. This is because treatments (such as eye creams, balms or lotions) are unable to penetrate deep enough into the skin. In this case, either dermal filler (often known as 'tear trough' injections) or surgical fat transfers are likely to be an option."