Why does the eye become red?
Common causes include dry eye, allergy, conjunctivitis and irritation, but inflammation, injury, corneal disease and acute pressure problems can also cause redness.
Warning symptoms
Reduced vision, moderate or severe pain, marked light sensitivity, significant swelling, trauma or contact-lens use with pain should prompt an eye examination.
When should you seek care?
Persistent redness or a red eye associated with pain or visual change should be assessed promptly to distinguish surface irritation from more serious eye disease.