Most causes of bloodshot eyes aren't dangerous. Eye redness is usually short-lived and resolves on its own. However, it can sometimes be a sign of a serious condition that requires treatment, such as a severe infection, a corneal ulcer, or glaucoma.
If you're not sure if you should see your healthcare professional, consider your other symptoms. Bloodshot eyes accompanied by any of the following warrant a medical evaluation:
This article discusses each of these in detail, less-concerning causes of red eyes, and how a provider will come to reach a diagnosis.
The additional symptoms that can indicate a serious cause of bloodshot eyes don't all point to the same diagnoses.
Seeking medical treatment at the first sign of a problem can help you get a proper and prompt diagnosis, prevent more serious issues, and preserve your vision. In some cases, urgent medical attention is recommended.
Blurry vision is a symptom of many neurological disorders, as well as conditions that affect the eyes. If you have blurry vision with eye redness, this combination may be caused by a serious eye problem. An autoimmune disorder, severe infections, and edema (swelling) are some of the causes of a red eye with blurred vision.
Don't delay in getting a medical evaluation if you are having these symptoms.
Conjunctivitis, a common viral infection, often referred to as "pink eye" may cause discomfort or scratchiness of the eye, but not extreme pain.
Severe eye pain should always be evaluated as soon as possible—eye 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, which is extreme sensitivity to light, is common with migraines and after head injuries. Along with eye redness, it can also be a symptom of eye irritation, inflammation, or any type of damage to the eye.
It can also be caused by iritis, 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. It can be caused by an autoimmune disease, a reaction to a corneal abrasion, trauma, or ulcer, or it may be idiopathic (without an identifiable cause).
Colored halos are a symptom of cataracts, corneal edema, and acute closed-angle glaucoma. These conditions can also cause redness of the eyes, but that is not always the case.
When you have swelling in your eye, the cornea becomes thicker. As it thickens, it also becomes cloudy. When this occurs, light scatters and we see halos.
This can be caused by a chronic disease process, or it can develop rapidly. You should see a healthcare professional if are seeing halos around lights.
If you have any fluid, pus, or blood in or around your eye, this could be due to a serious infection or a result of trauma. Sometimes, bleeding can occur even without trauma if you are taking a blood thinner or if you have a bleeding disorder.
Get medical attention right away if you have any type of discharge around your eye.
If you don't have these other symptoms, it's likely that your red eyes are due to something benign like dryness, allergies, or an irritant (like smoke in the air).
In this case, the redness will go away on its own in a day or two. In the meantime, you can avoid making it worse by taking the following precautions:
If your eyes are red and itchy as a result of allergies, you can try using over-the-counter eyedrops to relieve your symptoms. Artificial tears can also help with dry eyes.
An over-the-counter eyewash solution may be helpful, too.
If you have red eyes that don't improve on their own within a few days or get worse over time, you should see a healthcare provider—even if no other symptoms arise.
An ophthalmologist will evaluate your eyes with an examination and by asking questions about your symptoms and health history. Some of these questions may include:
Depending on your symptoms, your healthcare provider may take a sample of the fluid in your eye, test how your pupils respond to light, or ask you to read an eye chart.
Most of the time, red eyes are not a reason to worry. They will usually resolve on their own in a day or two. Sometimes, though, red eyes can be a sign of a more serious condition.
If you have red eyes accompanied by blurry vision, pain, or discharge, if your eyes are sensitive to light or you are seeing halos, see your eye healthcare provider right away.
What are the most common causes of red eye?
Some common causes of red eye include:
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.
Why has my eye gone bloodshot for no reason?
Eyes that suddenly become bloodshot may be irritated by airborne allergens or may simply be fatigued. Wearing contact lenses for a long period of time can also be to blame. See a healthcare provider if things don't improve in a day or two.
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Uveitis. National Institutes of Health. National Eye Institute.
Upadhyay MP, Srinivasan M, Whitcher JP. Diagnosing and managing microbial keratitis.Community Eye Health. 2015;28(89):3–6.PMID: 26435583
Digre KB, Brennan KC. Shedding light on photophobia. J Neuroophthalmol. 2012;32(1):68–81. doi:10.1097/WNO.0b013e3182474548
Cleveland Clinic. Red eye.
American Academy of Opthalmology. Why are my eyes bloodshot when I wake up?
By Troy Bedinghaus, OD
Troy L. Bedinghaus, OD, board-certified optometric physician, owns Lakewood Family Eye Care in Florida. He is an active member of the American Optometric Association.
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