Frankly, it will depend on the situation of your black eyes. On one hand, if you just have the black eyes, and there is no broken skin, and why not take a shower when you want. Just go ahead if you like. While taking the shower, just remember to be careful enough in case you will hurt the black eyes. On the other hand, if you find some broken skins or cuts around the black eyes, I think you had better not. Because you know you will let the water flow through our full body and if the water flow onto the cuts, then it is very easily to get infected and then the black eyes will get worse, also it will be more painful. Because of the fact, you just can take a shower on condition that your black eyes are recovered. Pls no worries, it will not take too long, and it will take about one week. Apart from taking shower, when you are doing some other things, you also should be careful.