An eye cold sore is commonly associated with herpes simplex keratitis, also known as eye herpes. Caused by the herpes simplex virus (HSV), these same cold sores appear in other areas of the body, like around the mouth and lips.
They are one of the leading infectious causes of blindness in the US, so it’s important to seek treatment immediately when you have these sores.
Keep reading to learn all you need to know about avoiding this severe eye infection and managing it if you are already infected.
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Herpes simplex virus (HSV) causes herpes simplex keratitis. Herpes is only contagious through direct skin-to-skin contact. Oral contact from kissing or unprotected sex are the main activities that expose you to asymptomatic herpes.
Although HSV-1 is the more common contagious agent, you may also get eye herpes when you have contact with HSV-2, the common contagious agent responsible for genital herpes.
Upon contact with the herpes virus, it resides in nerve roots and spreads to the sensory nerve ganglia. There is no cure, and it remains dormant without any symptoms. At this stage, it is very easy to contract herpes from an infected person, as no symptoms alert you of its presence.
Certain stressors may reactivate the herpes virus. Some flare-up triggers include:
Physical trauma from injury, surgery, or dental procedures
Weakened immune system from other infections or chemotherapy
When the virus spreads to the eye, you may experience varying levels of symptoms, some more severe than others.
Keratitis is the general term for any inflammation of the cornea, and the basic infection associated with herpes starts in the cornea’s top superficial layer. This more subtle infection is epithelial keratitis.¹
In more severe cases called stromal keratitis, the herpes virus infects the deeper layer of the cornea, causing scarring. This commonly leads to blurred vision, requiring a cornea transplant to fix the issue.²
Eye herpes can also cause glaucoma, affecting the optic nerve connecting to the brain. In the most severe cases, it causes a permanent loss of vision. Thankfully, proper management of the condition means most people with the infection don’t experience these issues.
Regardless of the type of herpes simplex keratitis infection you have, you may also see infections in other areas of your eye. These include:
Conjunctivitis: An active infection and inflammation of the thin transparent membrane of the eyelid (conjunctiva) and white part of your eyeball
Blepharitis: Direct inflammation of the eyelids due to cold sores
Iridocyclitis: Inflammation of the colored part of your eyeball
Retinitis: Inflammation of your retina or pupil, the tiny spot in your eyeball that controls your visual imagery
All these come in different levels of severity, just like the keratitis infection. Managing them at the earliest stages can prevent more consequential flare-ups.
When all these infections come together, you will have a barrage of uncomfortable symptoms to deal with. Some of these symptoms include:
Redness in the eye
Watery discharge from the eye
High sensitivity to light
When it comes to herpes keratitis, you’ll typically only have one infected eye. If you simultaneously experience a number of these symptoms in just one eye, there’s a high chance the cause is herpes simplex.
As there is no cure for eye herpes, the solution is to use treatments that keep the virus dormant as long as possible.
Once you receive a diagnosis, your doctor can prescribe eye drops and oral antiviral medications to manage symptoms and flare-ups. In more severe cases, you may need a surgical cornea transplant or laser tissue removal to correct lasting damage.
Cold sores on your eyelids are common symptoms of herpes simplex keratitis or eye herpes.
As herpes isn't curable, avoid direct contact with cold sores, practice safe sex, and avoid sex altogether during flare-ups. If you already have herpes and you’re worried it’s spread to your eye, get tested as soon as you suspect an infection and use your medication as prescribed by your doctor.
Eye herpes is more common in US adults under 30 from lower socioeconomic groups.
Herpes simplex flare-ups get better after two weeks of treatment. 67% of people with an eye herpes infection experience a recurrence within seven years.³
Touching your eye after touching a cold sore is one of the most common ways of contracting eye herpes from someone else. However, if this cold sore is on your body, the chances of contracting eye herpes are low, as you typically have antibodies against it at this point.
Visual impairment from herpes simplex occurs in less than 3% of people every year.⁴
Severe cases of herpes simplex infections could lead to encephalitis, a form of infection that can cause brain damage, memory loss, and death.
A misdiagnosis is the common cause of a lack of responsiveness to eye herpes treatment. Instead, your doctor may diagnose a Acanthamoeba infection, an equally severe condition that may lead to vision loss.
CKS is only available in the UK | National Institute for Health and Care Excellence
Chapter 68 herpesviruses (1996)
Basics of HSV (herpes simplex virus) keratitis | Centers for Disease Control and Prevention
Clinical management guidelines | The Collage of Optometrists
Ocular herpes simplex (2008)
Herpes simplex keratitis (2022)
How easy is it to spread genital herpes to the eyes? | American Academy of Opthalmology
Herpes simplex encephalitis (2022)