Conjunctivitis, commonly called "pink eye," is an infectious and contagious eye condition that affects the fluids and moist tissues that cover the eyeball and line the inner eyelid. Whether the condition is bacterial or viral, conjunctivitis does not affect the eye's vital inner structures and therefore does not threaten to damage vision. Since symptoms are so similar, it may be difficult to tell the difference between viral and bacterial pink eye.
Check both eyes
Check both eyes. Bacterial conjunctivitis often spreads to both eyes, while viral conjunctivitis often only affects one eye, according to AllAboutVision.com. With strict hygiene (and no touching of the affected eye), the spread of the viral type of conjunctivitis can be easily prevented.
Evaluate the discharge. Bacterial conjunctivitis has a heavier discharge than viral conjunctivitis. When the eye is experiencing a bacterial infection, the discharge is often thick and greenish in color, according to AllAboutVision.com. Viral conjunctivitis is characterized by excessive watering, rather than heavy discharge.
Record the eye condition upon waking. Bacterial pink eye often makes opening the eye difficult in the morning because of crusting that has formed overnight (especially for children), according to MedicineNet.com. An eye affected by viral conjunctivitis might be slightly sticky upon waking, but it won't have the crust that makes it difficult to open the eye.
Consider other illnesses. Viral conjunctivitis is the type associated with the common cold and is often accompanied by other symptoms, such as a runny nose and sinus congestion.
Check the lymph nodes around the ear and neck. Tender lymph nodes are associated with viral conjunctivitis, not bacterial.
Consider duration of the condition. NetDoctor.co.uk reports that bacterial conjunctivitis will clear up on its own without treatment in 64 percent of cases. Viral conjunctivitis may continue for a prolonged amount of time, depending on hygiene habits, and there is no effective treatment.