Six reasons the skin around your eyes looks tired
It is the thinnest skin on the body and it is the first place anything shows. Some of what happens there is fixable in a week and some of it is not fixable at all, and it is worth knowing which is which before spending anything.
It is dry, more often than it is anything else
Thin skin with very few oil glands loses water fast, and dryness there reads as tiredness rather than as dryness. This is the most common cause and the most responsive one, which makes it the sensible place to start.
Concealer sitting in the texture
Makeup over a dry, finely textured surface settles into it and makes the thing it was covering more obvious by mid morning. Hydrating first and giving it a minute changes the result more than a different concealer will.
Fluid, in the morning only
Puffiness from lying flat, which moves within the hour. If it is gone by the time you get to work, it is this, and there is nothing to buy for it.
Rubbing
Hay fever, tiredness, taking off eye makeup with force. The skin there does not take repeated pulling well and a lot of the crepey look people attribute to age is partly this. Gentler removal is free.
Colouring you were born with
Some darkness under the eyes is pigment or the vessels showing through thin skin, and it runs in families. No cream changes it, and products that promise to are the main reason this whole category has a reputation.
Sleep, again
It shows here before anywhere. Worth saying plainly because the eye cream aisle is largely built on people trying to buy their way out of this one.