Red eyes occur when the vessels in your eye become swollen or irritated. Discover when to see a doctor, treatment, and more. A red eye or pink eye , commonly referred to as bloodshot eyes , presents as the visible redness of the white part of the eye (sclera). This discoloration occurs when the blood vessels on the surface of the eye become dilated or enlarged. The appearance of red eyes can vary, ranging from a subtle pinkish tint to a more pronounced and deep red hue. Eye redness can be caused by allergies, infections, or fatigue. Treat your red , irritated eyes with these simple, natural remedies. Your eyes get red when the tiny blood vessels on the whites of your eyes expand and turn the whites pink or red . Learn about the causes & treatments for red eyes .