Is red eye contagious?

Infectious conjunctivitis can pass through contact with eye discharge, hands, towels, cosmetics, pillowcases, or shared surfaces. Viral infection often causes watery redness and may occur with cold symptoms. Bacterial infection may cause thicker discharge and eyelids that stick together. A red eye caused by pollen, dust, smoke, a contact lens problem, or dryness is not contagious, although it can look similar.

Wash your hands after touching your eyes, use separate towels and pillowcases, avoid sharing eye drops or makeup, and clean discharge gently with fresh cotton or a clean wet cloth. Do not wear contact lenses until the eye has recovered and a clinician says they are suitable again. Avoid rubbing the eye, and stay home from close-contact activities if discharge is active or a clinician has advised precautions.

Arrange prompt medical assessment for eye pain, light sensitivity, blurred vision that does not clear after blinking, marked swelling, injury, chemical exposure, or a red eye in a contact-lens wearer. Seek urgent care if vision changes suddenly or pain is severe. A clinician can distinguish infection from allergy or another eye problem and advise when close contact is reasonable.

Could this be infectious conjunctivitis or an allergic reaction? How long should I avoid contact lenses, eye makeup, swimming, or sharing towels? What changes would mean I need an urgent eye examination?