I strongly recommend returning to both the eye doctor and a dermatologist. While it isn't common, blindness can be caused if the shingles virus infects the eye. If the blisters are anywhere near his eye, this can be a concern. It is also possible that the anti-viral they have him on simply isn't effective for him. I was prescribed two different anti-virals to treat my shingles outbreak last fall because the first wasn't giving the results we wanted, probably due to an incompatibility with my own body chemistry(that's what the dermatologist told me).
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