In this blog I will be covering a disease that almost everybody had at least once in their lives. This disease is known as conjunctivitis, or more commonly known as “pink eye”. There are several pathogens that cause disease; these include both bacteria and viruses. However in this entry three of the main of the viruses that cause this disease will be discussed which are measles virus, adenovirus, and Herpes simplex virus (HSV).  These viruses when dealing with conjunctivitis have the same modes of transmission, effect on body and complication. Initially to contract this virus there has to be direct contact, an example would be rubbing the infected the eye of the person that has the disease and then touching the hand of another person who will, in turn, accidently touch their eye and get it infected. The reaction to this would be a cytopathic effect (is damage that virus causes when it invades the cells of the host), which results in the inflammation of the eye. This could evolve to keratitis, which in its superficial state heals and doesn’t leave scars, but in its deeper states in effects layers of the cornea, which causes scars and damage to the vision. There is no known vaccine for conjunctivitis but it usually heals rapidly and without any complications if the patient is using the eye drops that are prescribed by the physician or any other method.  Since not being careful could lead to keratitis, as was mentioned earlier, and could lead to scarring that is quite evident if it reaches the deeper levels of the cornea.