Everyone gets red eyes from time to time when blood vessels well or dilate. It's usually due to eye dryness, allergies, sun exposure, or dust. Interestingly, regular eye redness has been linked to depression — particularly among Olds. If your eyes are red for more than a couple of days in a row, see your doctor for a formal diagnosis. You could have Sjögren's syndrome, a common autoimmune disease, an infection, blood vessel abnormality, or something even more serious. Alternatively, you are Voldemort.