This is relatively common and may be due to a variety of agents. Adenovirus or picornaviruses are the most common causes of viral conjunctivitis.
You can soothe the discomfort of viral or bacterial conjunctivitis by applying warm compresses to your affected eye or eyes. To make a compress, soak a clean cloth in warm water and wring it out before applying it gently to your closed eyelids.
For allergic conjunctivitis, avoid rubbing your eyes. Instead of warm compresses, use cool compresses to soothe your eyes. Over-the-counter eye drops might also help. Antihistamine eye drops can alleviate the symptoms, and lubricating eye drops can rinse the allergen off the surface of the eye.
See your doctor of optometry if you think you have conjunctivitis. He or she can diagnose the cause and prescribe the proper treatment.