Eye herpes almost always comes from the same virus that causes cold sores, herpes simplex virus type 1 (HSV-1). Most people don’t “catch” it in their eye from someone else. Instead, the virus travels to the eye from another part of their own body, usually the mouth, either during a first infection or when a dormant infection reactivates later. Globally, an estimated 1.8 million people develop herpetic eye disease each year, and roughly 230,000 of those cases result in vision impairment in one eye.
The Most Common Route: Self-Transmission
The majority of eye herpes cases happen in people who already carry HSV-1 somewhere else in their body. If you’ve ever had a cold sore, you carry the virus. It lives permanently in a cluster of nerve cells near your jaw called the trigeminal ganglion. One branch of that nerve bundle runs to your mouth and lips. Another runs directly to your cornea.
When the virus reactivates, it can travel along nerve fibers toward the eye instead of (or in addition to) the lips. This is why most eye herpes isn’t a new infection at all. It’s a flare-up of a virus you’ve carried for years or even decades. You don’t need to physically touch a cold sore and then rub your eye for this to happen, though that’s certainly possible too. The virus can reach the cornea entirely through internal nerve pathways without any hand-to-eye contact.
That said, direct transfer via your hands is a real and preventable risk. Touching an active cold sore and then touching your eye, or inserting contact lenses without washing your hands, can deliver the virus straight to the corneal surface. This is especially relevant during an active outbreak when viral load is highest.
Catching It From Someone Else
Direct transmission from another person to your eye is less common but possible. HSV-1 spreads through close contact with an infected person, typically through kissing, sharing utensils, or skin-to-skin contact. If someone with an active cold sore touches or kisses near your eye area, the virus can be introduced directly. HSV is only found in humans, and it requires direct contact to spread.
HSV-2, the strain associated with genital herpes, rarely causes eye infections. When it does, it’s typically through oral-facial contact with genital lesions. The one notable exception is newborns: babies can acquire HSV-2 as they pass through the birth canal of a mother with an active genital herpes infection. Neonatal herpes occurs in roughly 1 in 3,000 live births in the United States, and about 4% of those cases involve eye damage along with other serious complications.
What Triggers a Flare-Up
Since most eye herpes results from reactivation of a virus already living in your nerve cells, the triggers matter as much as the original infection. The Herpetic Eye Disease Study, a major clinical research effort, identified three proven triggers: UV light exposure, fever, and refractive eye surgery (like LASIK). Psychological stress is commonly blamed, but that same study group found it difficult to confirm as a true trigger, possibly because stress is so widespread that isolating its effect is nearly impossible.
Any event that suppresses your immune system can create an opening for the virus. A bad cold, a sunburn, or recovery from surgery can all give the dormant virus a chance to reactivate and travel along the nerve toward the cornea.
What Eye Herpes Looks and Feels Like
The most common form of eye herpes affects the cornea, the clear front surface of the eye. Early symptoms often mimic pink eye: redness, tearing, light sensitivity, and a gritty or painful feeling. You might notice blurred vision in one eye. It’s almost always one-sided, which is a distinguishing feature.
The hallmark sign that separates herpes from other eye infections is a branching, tree-shaped ulcer on the cornea called a dendrite. An ophthalmologist can spot this pattern using a slit-lamp microscope and a fluorescent dye that highlights damaged cells. In typical cases, the clinical appearance alone is enough to confirm the diagnosis without lab testing. More severe forms can involve deeper layers of the cornea, the interior of the eye, or the retina, and these carry greater risk to your vision.
How to Reduce Your Risk
You can’t eliminate the virus once it’s in your body, but you can lower the chance it reaches your eye. The single most important habit is hand hygiene. Wash your hands thoroughly before touching your eyes, especially if you have an active cold sore or feel the tingling that precedes one. This applies doubly if you wear contact lenses, since inserting and removing lenses means repeatedly touching the eye surface.
Protecting your eyes from excessive UV exposure with sunglasses may help reduce reactivation, given that UV light is one of the confirmed triggers. If you’re prone to cold sores and are considering LASIK or other corneal surgery, discuss your herpes history with your surgeon beforehand, since the procedure itself is a known reactivation trigger.
Avoiding direct facial contact with someone who has an active cold sore is straightforward but worth stating. Don’t share towels, washcloths, or eye makeup with someone during an outbreak. And if you have a cold sore, resist the urge to touch it and avoid rubbing your eyes until it has fully healed and you’ve washed your hands.