Here are some GREAT products for getting rid of undereye circles. I'm currently suffering from that problem and aside from getting 8 hours of sleep and cutting own on your salt intake. Here are some great products to get rid of your dark under eye circles.
Quintessense Under Eye Serum Capsules are great for thickening the skin under your eyes so that they are firm and circles are less apparent.
Murad Lighten and Brighten Eye Treatment contains 2 percent hydroquinone which is a bleaching cream that is specifc to your under eye area. This product is safe and its not extreme at all, but it will accomplish its duty. It is a MUST that you wear your sunblock with this product.
SkinCeuticles Pigment Regulator is a great skin brightening option is your nervous about doing skin bleaching under your eyes and if your skin is sensitive.
Tea Bags are great for taking down the puffiness of your eyes and taking away discoloration.
I am setting up a routine with these products and I will let you know how it goes. Let me know more secrets if you have any!