Hi, conjuctivitis commonly caused by a bacterial or viral infection or an allergic reaction. It may affect one or both eyes. Its signs and symptoms include:Redness, Itchiness,a gritty feeling,a discharge that forms a crust during the night that may prevent your eye or eyes from opening in the morning,Tearing. Causes of pink eye include: Viruses,Bacteria,Allergies,a chemical splash in the eye, and foreign particle.precautions: if you are using contact lenses, stop the use, don't touch the normal eye with the hand that had contact with infected eyes, it can spread from one person to other person also so you need treatment according to the cause.consult ophthalmologist for furthur evaluation and treatment.