What Causes Red Line In Eyes After Suffering From Shingles?

Hi, I had shingles 6 weeks ago on the right side of my face around the eye. I took anti viral medication and the shingles seems to have dried and reduced. However, there is a red line (vertical) on the white part of my eye. It has been lingering over 6 weeks. When I press the edges of the eye, there is still a dull weak pain. I have checked with an ophthalmologist and he has confirmed that my eye has not been infected. I took steroid drops for a few weeks in the beginning, but he suggested to not over do it. So, I have been off the steroid drops for over 2 weeks now. As the red line in the eye is still there after 6 weeks. I feel that it is getting weaker but taking too long for it to go away. Is there a anti-viral medication just for the eye that I should take. Will a Shingles vaccine help. Any other suggestion.