Well, generally speaking, dehydration can lead to eye bags under eyes. For the dehydration, according to many experts, it is a condition that occurs when the loss of body fluids, mostly water, exceeds the amount that is taken in. so it can lead to the water go out of the body and there is no enough water for the organs to work. In this way, our body can be disordered and in serious case, it can affect our eyes and lead to some eye diseases, such as bloodshot eyes, red eyes, even dark circles and eye bags under your eyes. Of course, in serious cases, it can be a risk of your life. So you should drink more water and eat more fruits to make sure you have enough water intakes. Also, you can use some cool cucumber on your eyes. Besides, you should know that lack of sleep and stress can lead to eye bags too. anyway, just be careful.