My aunt says the bottom half of her eyes are red. i checked them out and they are red, no sign of fever or anything else. what could this be?

Many possibilities: "red eyes" can be caused by infection (either viral or bacterial), allergies, trauma, or issues with the eye itself (acute glaucoma). Is she having other symptoms (such as itchiness, fever, runny nose, pain, vision changes)? The most concerning could be vision changes or pain of the eye itself.

Blood: Is it where the white part of the eye (sclera) usually is? If so, it is usually benign and will clear with time (1-21 days), use artificial tears and if vision changes see your eye doctor. Or is it in the tears and you can wipe it off with a tissue? This could be many things, a tumor infection of the tear drainage system, a viral infection, a hemangioma under the lid, etc. See and eye md.