Pink eye, or conjunctivitis, is an infection/inflammation of the conjunctiva, which is the transparent membrane that serves as a covering for the white part of the eye (called the "sclera"). In addition to inflammation, eyes affected with conjunctivitis will usually tear up with a sticky discharge. This discharge develops into a crust during sleep, making it difficult for the patient to open their eyes in the morning. True "pink eye" is actually a viral infection and is very contagious.
Many conditions other than pink eye can also cause our eyes to be red. Here are the 3 major causes of eye redness:
Streptococci and staphylococci are the bacteria that are most often responsible for bacteria-related eye redness. However, chlamydia and gonococci can also cause red eyes. Bacterial eye infection is accompanied by serious eye pain, itching, swelling, redness, and discharge. The spread of bacterial eye infection usually results from sharing items such as makeup or makeup tools that have been infected with bacteria, or by touching one's eyes with dirty hands. If not treated, a bacterial eye infection can last for more than 10 days, but if treated, it should resolve in a few days.
Eye redness caused by allergies can be followed by serious itching and tearing of the eyes. Pain can be minimal, but allergy-related eye redness typically comes with quite a bit of discomfort. Allergens that trigger allergic-type red eyes include grass, dust, pollen, mold, and ragweed. Eye redness caused by allergies is not contagious.
When a virus is the cause, patients typically experience teary discharge accompanied by nasal congestion, puffy eyelids, runny nose, and sharp pain. This is usually contracted through exposure to cough and sneeze droplets from an infected individual. Viral infections can take as long as 2 weeks to treat, depending on the seriousness of the infection.
The best way to prevent pink eye is by practicing good hygiene:
Avoid putting dirty hands in your eyes
Make it a habit to wash your hands often
Avoid sharing towels, makeup, or other personal items
Changing your pillow cover regularly