Eyes in which the sclera (the whites of the eye) and/or conjunctiva (the inside of the eyelid) are colored red due to the prominence of superficial blood vessels. Bloodshot eyes can be the result of a wide range of conditions, including tiredness, eyestrain, irritation, conjunctivitis, injury, or more serious inflammatory conditions. I've got these really bloodshot eyes from studying all night long. Honey, those bloodshot eyes look terrible! I think we need to get you to the doctor.