A story in the Daily Express on 2nd August 2022 described how a facial infection can reactivate in the eye. This ocular herpes needs to be treated.
“Ocular herpes usually occurs when a previous infection with the virus reactivates and spreads to the eye. Most people will catch the herpes simplex virus as children, but will not notice it as there are often no symptoms.”
“Common symptoms of herpes simplex keratitis include redness around the front of the eye, pain, aching or a gritty feeling as well as sensitivity to bright light.”
Both of these quotes are true. And the warning that if you feel this sort of eye problem, and you have had a cold sore in the past, it is important to mention the cold sore to the ophthalmologist.
The article however failed to mention one very useful fact.
Herpes infection will affect one eye only.
Just like a cold sore on the face, or anywhere else, the infection will appear on one side only. This is because it is happening when a recurrence of a facial cold sore uses a different nerve within the affected dermatome. The herpes simplex virus reactivates and appears in one eye only.
Any problem with both eyes will have a different cause.
Cold sores in the eye, ocular herpes, are treated with a special antiviral eye ointment. Antiviral pills – and sometimes other medications – may also be prescribed. This depends on how bad the infection is.
Obviously, as with any herpes simplex recurrence, the sooner treatment is started, the better. So:
A person who has had cold sores, and gets one sore eye, needs to get it looked at in case it is ocular herpes.
More information about ocular herpes on NHS Choices