The main cause of Bloodshot eyes is cold or inflammation, and they need as much rest as possible. Use an eye mask and eye drops or an eye bath, whichever is easiest, to help soothe this condition. If eyes are not only red, but itch and are giving off a sticky discharge, then you're probably suffering from inflammation of the membrane of the eyelids and eyeball, or conjunctivitis. This can be caused by a smokey atmosphere, too bright a light, dust, colds, injury, or infection. An irritating substance, such as mascara or eye shadow, can also bring about conjunctivitis, so obviously, no eye makeup should be worn whilst the problem clears itself, and afterwards, change your eye makeup to a pure, umperfumed, hypoallergic makeup that is especially made for sensitive Oyes. If there is no improvement after a few days, see your doctor.