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Red eye is not a single disease process, so there also is no single treatment. When doctors use the term, red eye, we are usually referring to a symptom that causes a patient to seek medical care, and we then perform an evaluation to find a specific cause.
There is a term used by laypersons, called pink eye, that is used to describe mild diffuse redness that is seen with conjunctivitis, inflammation of the lining over the whites of the eye. But even conjunctivitis has several causes, including both viral and bacterial infections, as well as allergies.
In addition to conjunctivitis, there can be inflammation or infection of other parts of the eye that can cause redness of the eye. Red eye can also occur from glaucoma, injury to the eye, excessive dryness of the eye, and bleeding under the conjunctiva, also called subconjunctival hemorrhage. This latter condition is actually very common, and while it looks very bad, with an amount of blood that can appear frightening, it is actually a benign condition that usually requires no treatment. Bleeding can occur from trauma, but it is more often seen from sudden pressure that is transmitted to the eye from the chest and neck, such as can occur with coughing or sneezing.
Since it can be caused by various conditions, the usual recommendation is that you should be seen quickly if there is eye redness that is associated with altered vision or other symptoms, such as headache, nausea, or vomiting, or significant swelling of the eye or around the eye. If there is redness without other symptoms, it is OK to give it a few days to see if it clears up spontaneously, as we see with a hemorrhage, but if the redness without symptoms persist, it would be appropriate to see your doctor.
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