I have always been very fair skinned with a fairly decent complexion. Through the years I've used very little make-up often using only a light concealer (I use Cover Girl) to cover any irregularities in skin tone and the dark circles I would get under my eyes when my allergies were acting up.
Unfortunately last year I was diagnosed with glaucoma having now to use daily drops in my eyes, and those drops have turned the skin under my eyes and my eyelids very dark. I look like a demented raccoon with red rimmed eyes. So I went in a search for a concealer that would cover this level of darkness and would last awhile. The Cover Girl I had been using definitely wasn't up to the task. After a bit of research I found Revlon's Age Defying concealer and it's great! Not too expensive, about $4.95 for a tube that lasts me a couple of months, and I use it every day, twice a day if we're going out in the evening.
So I give it a strong recommendation if you've got raccoon eyes and are looking for a good concealer.