Red eye is a common problem that can happen in one or both eyes. The redness comes from the blood vessels on the surface of the eye. These blood vessels expand due to irritation or disease.
Seek immediate medical care if:
- Your eyesight changes suddenly.
- Red eye happens with a bad headache, eye pain, fever or if light starts to hurt your eyes.
- You also have an upset stomach or are throwing up.
- Red eye is caused by an object or chemical splashed in your eye.
- You suddenly begin to see circles around lights.
- You feel as if something is in your eye.
- You have swelling in or around your eye.
- You cannot open or keep your eye open.
When to make an appointment with a healthcare professional
Sometimes, having red eye for a short time is not a reason to worry. If you think the redness is caused by over-the-counter eye drops, try a different brand or take a break from using them.
Call a healthcare professional for an appointment if you have red eye that doesn't clear up after several days, especially if you have thick pus or mucous for week or more.
Contact your eye care professional if:
- You're having eye redness with pain.
- You've had eye surgery or an eye injection in the past.
Show References
- Eye pain. Merck Manual Professional Version. https://www.merckmanuals.com/professional/eye-disorders/symptoms-of-ophthalmic-disorders/eye-pain. Accessed Oct. 17, 2024.
- Jacobs DS. The red eye: Evaluation and management. https://www.uptodate.com/contents/search. Accessed Oct. 17, 2024.
- Ferri FF. Differential diagnosis. In: Ferri's Clinical Advisor 2025. Elsevier; 2025. https://www.clinicalkey.com. Accessed Oct. 17, 2024.
- Leonardi A, et al. Office-based ocular procedures for the allergist. Current Opinion in Allergy and Clinical Immunology. 2019; doi:10.1097/ACI.0000000000000563.
- Pain in eye. American Academy of Ophthalmology. https://www.aao.org/eye-health/symptoms/pain-in-eye-3. Accessed Oct. 17, 2024.
- Skorin L, et al. Ectropion: Classification, diagnosis, and management. Consultant. 2018;58:e180.
- Walls RM, et al., eds. Red and painful eye. In: Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Elsevier; 2023. https://www.clinicalkey.com. Accessed Oct. 17, 2024.
- Dry eye. American Academy of Ophthalmology. https://www.aao.org/eye-health/diseases/what-is-dry-eye. Accessed Oct. 17, 2024.
- Eye infections from contact lenses. American Academy of Ophthalmology. https://www.aao.org/eye-health/diseases/contact-lens-related-eye-infections. Accessed Oct. 17, 2024.
- Bonini S. The red eye. European Journal of Ophthalmology. 2021; doi:10.1177/11206721211024827.
- Salinas R, et al. Floppy eyelid syndrome: A comprehensive review. The Ocular Surface. 2020; doi:10.1016/j.jtos.2019.10.002.
- Injections to treat eye conditions. National Eye Institute. https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/diabetic-retinopathy/injections-treat-eye-conditions. Accessed Oct. 17, 2024.
Original article: https://www.mayoclinic.org/symptoms/red-eye/basics/causes/sym-20050748