Causes of herpes simplex eye infections
NHS ChoicesMedical Reference
Herpes simplex eye infections are usually caused by the herpes simplex virus type 1 (HSV-1). The HSV-1 virus can also cause cold sores on your face and, rarely, genital herpes.
A herpes simplex eye infection can also be caused by the herpes simplex virus type 2 (HSV-2). HSV-2 can also cause genital herpes and, rarely, cold sores on your face.
Triggers of a herpes simplex eye infection
If you have been exposed to the herpes simplex virus, it will usually remain dormant (inactive) in your blood. But it can be activated by certain factors, which can then lead to symptoms.
These trigger factors include:
- another illness or an injury
- exposure to strong sunlight
- a fever (high temperature above 38°C)
- exposure to cold winds
- (in women) having your period
Having a weakened immune system can also trigger regular cold sores or herpes simplex eye infections - for example, if you have HIV or are receiving chemotherapy treatment.