There are many causes and types of conjunctivitis in both eyes, and conjunctivitis is divided into two categories: infectious conjunctivitis and non-infectious conjunctivitis. In the case of infectious conjunctivitis, such as bacterial conjunctivitis, the main cause is bacterial infection, which may be caused by improper eye hygiene or by the overproliferation of bacteria in the body due to a decrease in body resistance. There may also be bacterial infections caused by infection from others. In the case of non-infectious conjunctivitis, it is most often associated with exposure to specific substances or foods, in this case allergic conjunctivitis, which is the itchy, red and swollen eyes caused by exposure to allergens. Usually, both infectious and non-infectious conjunctivitis can cause bilateral attacks, and medication is administered mainly to both eyes until the symptoms are completely improved before considering discontinuing the medication.