Chemosis (or conjunctival chemosis) is a blister-like swelling of the conjunctiva, the clear membrane that covers the whites of your eyes. This symptom is most likely to happen with infections, allergies or injuries. It’s usually treatable and not serious. While it’s unlikely to be dangerous, it’s best to get it checked and treated sooner rather than later.
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Chemosis, also known as conjunctival chemosis, is the swelling of your conjunctiva, the clear membranes covering the whites of your eye and the inside of your eyelids.
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
Your corneas protect the pupils and irises of your eyes. Your conjunctiva are the outermost protective layer for the rest of the surface of your eye. Your conjunctiva also wrap around and cover the inside of your eyelids.
Chemosis can be hard to see unless you look closely. Smaller areas of chemosis on the white of your eye can look like a small, raised area or blister. These often have a slight yellowish tinge to them. Chemosis on the conjunctiva lining the inside of your eyeball can make your eyelid look puffy or swollen. When it’s severe, you might have trouble closing your eyes.
Chemosis happens when something damages or irritates your conjunctiva. Your body responds by sending additional fluid, blood cells, immune cells and more to the affected area. These things cause swelling.
Some of the most common causes are:
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Less common causes include:
There are many possible causes of conjunctival chemosis, and their treatments vary widely. Some examples of treatments include:
Other treatments might be necessary depending on what caused your chemosis. Your healthcare provider or eye care specialist is the best source of information about the treatment options they recommend for your specific case.
Conjunctival chemosis is often treatable when it’s mild or happens with causes that aren’t severe. The three main things you can do to treat it are:
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Some causes of chemosis are preventable, but many happen unpredictably or for reasons you can’t control. The steps you can take to prevent conjunctival chemosis include:
Chemosis needs medical attention when it’s more severe or when it happens with certain causes.
If you experience chemosis and any of the following apply, you should get medical attention as soon as you can:
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The above list contains just a few reasons to seek medical care for an eye-related injury or illness. When in doubt, you should always err on the side of caution and seek medical attention. Doing so can help you avoid long-term vision or eye issues.
How long chemosis lasts depends on many factors, especially what’s causing it. Some causes will go away within a few days. Others can last weeks or more. Your eye care specialist can tell you what you should expect with your chemosis and what you can do to make it easier for your eye to recover.
There’s no fast way to get rid of chemosis other than treating whatever is causing it. How long it takes to go away depends on what’s causing it, the treatment(s) you receive and more. Your healthcare provider can tell you about how long it should take to go away and what you can do to make that process happen as smoothly and quickly as possible.
A note from Cleveland Clinic
Just the thought of having blistering or swelling on your eye is enough to make anyone squirm. The most common causes of conjunctival chemosis are short-term conditions that are usually treatable and not severe. Something more serious — like a thyroid or heart problem — can also cause it, but instances like that are rare. If you have chemosis, talk to a healthcare provider. They can tell you more about the likely cause, treatments and what you can do to help it.
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Last reviewed on 01/29/2024.
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