Pink eye is one of the most common optical diseases, but there are myths on its causes and how it spreads that have gained considerable popularity through the years. Let’s take a look at a couple of the most popular sayings and examine them one by one.1,2
• Anyone With Pink Eye Can Infect You
This myth is only true to a certain degree. As you’ll learn later on in this guide, pink eye that is caused by viruses and bacteria are contagious, but pink eye caused by chemical irritants or allergens is not.
• If Your Eyes Are Red and Swollen, It’s Automatically Pink Eye
Due to the prevalence of pink eye among communities (especially schools), it’s easy to assume that once you see someone who has red, swollen eyes, he automatically has pink eye. This isn’t entirely the case, as there are other ailments that can cause irritated eyes.
When Is Pink Eye Contagious and When Is It Not?
As you’ve read in the myths listed above, some types of pink eye are not contagious. The first one is called “allergic conjunctivitis,” which occurs due to exposure to dust, spores and animal dander. These allergens cause swollen and itchy eyes, along with a burning sensation.3
The second non-contagious form is “irritant conjunctivitis.” This occurs when foreign objects get into your eye, such as shampoo, chemical fumes or a dislodged eyelash.
Normally, the irritation goes away shortly after the exposure is gone and when you’ve washed your eyes with running water. But if pain continues to linger, it’s best to visit a doctor immediately.4
The remaining two types of pink eye are contagious, namely viral and bacterial conjunctivitis. Viral conjunctivitis normally occurs when you have a cold, because virus-containing droplets from a sneeze may land on your eyes.
The same concept applies to bacterial conjunctivitis — contact into surfaces infected with bacteria, and then touching your eyes afterwards may result in infection. If you don’t wash your hands frequently, you may pass on the bacteria to others as well.