I think its not Lyme's disease and that there are many other things it could be. She needs to see an Eye MD ophthalmologist, not a non-physician limited scope optometrist.
Consider a second opinion ASAP. If a neuro-ophthalmologist is available that would be even better.
There is some urgency to make sure she does not have temporal arteritis because it can affect the other eye. Tests include Sedimentation rate, C-reactive protein and possibly temporal arter biopsy.
Other common problems: anterior non-arteritic ischemic optic neuropathy, retinal artery and vein occlusions.
JCH III MD