A black eye causes swelling and black-and-blue discoloration of the eyelids and soft tissues around the eye.
Sometimes, trauma that results in a black eye also causes small areas of bleeding on the white of the eye and on the inner lining of the eyelids. If you have bright-red or dark-red discoloration of your eyeball, you have another problem. This discoloration most likely is caused by a condition called a subconjunctival hemorrhage, which means a small blood vessel in the eye breaks and bleeds. This bleeding can be caused by trauma or by retching or vomiting. Like a black eye, the color change from a subconjunctival hemorrhage typically goes away slowly on its own, and the condition does not need any treatment.