Pink eye or cold and allergy eye symptoms - what are the differences?

Red eye: Pink eye is usually due to a bacterial infection, the lids get mattery, crusty, and stuck shut. Allergies make the surface of the eye red and produce a clear watery discharge, and is usually associated with some itching, and if you rub the eye you can get it secondarily infected and end up with a pink eye condition in addition. A cold is associated with a clear discharge and it can be infected.