Warning Signs That Your Red Eye Could Be Serious

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Most of the time, a case of red eye is short-lived and disappears on its own. Sometimes, however, red eyes can be caused by a more serious condition. The following danger symptoms in a red eye should be evaluated by a medical professional.

close up of bloodshot eye
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Blurry Vision

Blurry vision is often associated with serious ocular disease. If your eye is red and your vision is blurry, something significant is going on. You need an evaluation to determine what is causing both symptoms.

When your healthcare provider checks your vision during a routine eye exam, it is a simple, quick way to determine the health of the eye.

If a patient can read the 20/20 line on the eye chart with ease, that tells the healthcare provider that light is being focused on the retina fairly accurately and the retina is processing the information correctly.

If your vision is acutely decreased with redness, this may indicate an issue in the transmission of light to the back of the retina due to a non-refractive issue. If your vision is blurry without associated redness, then it may be that you need vision correction or an update of your corrective prescription.

Severe Pain

Conjunctivitis may produce mild irritation or scratchiness, but not extreme pain. Severe pain is a symptom of keratitis, a corneal ulcer, iridocyclitis, or acute open-angle glaucoma.

Severe pain should always be evaluated as soon as possible as damage can occur in a short period of time. For example, a corneal ulcer caused by a bacteria called Pseudomonas can advance to a blinding eye infection within 48 hours if not treated.


Photophobia, or extreme sensitivity to light, is usually a symptom of iritis. Iritis is an inflammatory disorder of the eye in which the ciliary muscle behind the iris becomes inflamed and begins to spasm, causing the eye to feel sensitive to light.

Light sensitivity is also a general symptom that occurs when the cornea is irritated. A corneal abrasion or corneal ulcer can bring on debilitating light sensitivity.

Colored Halos

Colored halos are a symptom of corneal edema and acute open-angle glaucoma. Usually, halos seen around lights are caused by a disruption in the optical system of the eye.

The cornea, the clear dome light structure on the front part of the eye, becomes thicker, due to the swelling, or edema. As it thickens, it also becomes cloudy. When this occurs, light scatters and we see halos.

When to See an Eye Healthcare Provider

If you have red eyes accompanied by any of the warning signs above, call your eye healthcare provider. Seeking medical treatment at the first sign of a problem can help prevent more serious issues and preserve your vision.

Frequently Asked Questions

  • What are the most common causes of red eye?

    Some common causes of red eye include:

    If you're experiencing additional symptoms, including pain or discomfort, make an appointment with your ophthalmologist to help determine the cause. Seek medical treatment immediately for an eye injury.

  • How can you treat red eyes?

    You can treat minor cases of redness and irritation with rest, over-the-counter eye drops, gently washing eyelids, and cool compresses over the eyes. If you have additional symptoms or redness persists, see your eye healthcare provider.

  • What causes eye redness when you wake up?

    Eye redness in the morning may be caused by dry eyes. While you sleep, your eyes stop making tears to lubricate your eyes. Your eyes may get particularly dry at night if you have dry eye syndrome or blepharitis, or if your eyes don't close completely as you're sleeping.

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5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Uveitis. National Institutes of Health. National Eye Institute.

  2. Upadhyay MP, Srinivasan M, Whitcher JP. Diagnosing and managing microbial keratitis. Community Eye Health. 2015;28(89):3–6.PMID: 26435583

  3. Digre KB, Brennan KC. Shedding light on photophobiaJ Neuroophthalmol. 2012;32(1):68–81. doi:10.1097/WNO.0b013e3182474548

  4. Cleveland Clinic. Red eye.

  5. American Academy of Opthalmology. Why are my eyes bloodshot when I wake up?

Additional Reading
  • R. Douglasss Cullom, Jr., Benjamin Chang, The Wills Eye Manual Office and Emergency Diagnosis and Treatment of Eye Disease, 2nd edition. Rev. ed. of: Wills Eye Hospital Office and Emergency Room Diagnosis and Treatment of Eye Disease, 1990. ISBN 0-397-51380-1. Chapter Differential Diagnosis of Ocular Symptoms, Pages 1-6 and Differential Diagnosis of Ocular Signs; Pages 7-17.