Acivir Eye Drop is an antiviral medicine which treats eye infections caused by Herpes simplex virus. It works by preventing the multiplication of the virus on the surface of your eyeball (cornea). This stops the production of new viruses and clears up your eye infection. Acivir Eye Drop is for external use only. Use it in the dose and duration as advised by your doctor. Wash your hands before and after applying the medicine. Use it as long as your doctor has prescribed and do not stop using the medicine even if you get better. It may cause a stinging sensation and eye redness immediately following the application. However, these side effects are temporary and usually subside on their own. Inform your doctor if they persist for a longer duration. Do not wear contact lenses while using it.