If you or your loved one has ever had conjunctivitis, you’ve probably been warned by your eye doctor to be careful about spreading it to someone else. But just why is conjunctivitis so contagious? How can something that only affects your eyes be transmitted to someone else? The answer lies in how humans tend to behave as well as how the infection itself behaves.

Conjunctivitis Can be Bacterial or Viral

The important thing to know about conjunctivitis is that it can be caused by either a bacterial infection or a viral infection. Bacteria and viruses tend to behave in different ways and can be transmitted in different ways. Bacterium tends to be transmitted by direct contact. Imagine if you have bacteria on a tissue and then someone else picks up that tissue and the bacteria gets on their hands. Viruses may be transmitted through the air. The common cold is a virus that can be spread through sneezing or coughing. The virus particles travel through the air and then land on someone else. Because conjunctivitis can be either bacterial or viral, it is more contagious than some other infections.

The Incubation Period For Conjunctivitis is Long

Another reason that conjunctivitis is so contagious is that the incubation period is long. A person can be infected without exhibiting symptoms for between 24 and 72 hours. Since bacteria can survive on surfaces for around eight hours, you could accidentally be contaminating surfaces around your home, office, or classroom without realizing that you’re spreading conjunctivitis.

People Touch Their Eyes and Face All the Time

The main reason why conjunctivitis spreads so easily has to do with how people behave. While reading this article you probably touched your face at least once. People unconsciously touch their eyes and faces all the time. If fingers have come into contact with conjunctivitis, that gets transmitted into the eyes.

If you do develop conjunctivitis, do your best to stay home and wash your hands often. This will help to contain the spread.