Shingles is caused by the varicella-zoster virus — the same virus that causes chickenpox.If you’ve had chickenpox, the virus can lie dormant in your body’s nerve tissue for years when suddenly it’s triggered by stress or a weakened immune system, and manifests as shingles.
https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-minute-what-are-eye-shingles/

