It may be caused by chalazion cyst, which is a sort of like a pimple on your eyelid. If you unfortunately suffered from it, Your eyelid will appear red. If so, you shall consult a doctor and treat it as soon as possible. Apart from chalazion, icky is another possibility to cause bump on the eyelid. Since this is a matter of your eyes, you shall treat bump on the eyelids seriously. But if the bump on the bottom eyelid is white, it maybe fat globules. If your eyes are in this satiation, don't worry, they are harmless.
I guess it may be a stye, but I am not that sure. You need to provide me with more information. Do you have any itchy feelings or anything wrong? However, I bet it may be just a small problem. You might as well wait for a few more days. If it goes away itself, then it is harmful. But if it doesn' t, you really need to go to an eye doctor as soon as possible.