Hopefully you have had your eyes checked by an opthamologist?
I have a grandson who had lots of vision problems before he was diagnosed. Blurry vision, and multi-colored circles which he would complain of periodically.
Once he got on treatment the vision things went away...with an occasional bout which would happen when he was herxing.
Lyme does affect the eyes in many...but clears up with treatment...hope yours will, too! 
For the double vision, see an opthamologist that specializes in glaucoma, irisitis, and uveitis. I am 57 yrs old, my eyes were like that for the last 5 years, only getting worse.
Took abx from Oct 2003 - Apr 2004. During that time my eyes were so much much better. When came off abx, a month later pain, double vision, loss of vision, headaches, spacey feeling, dry dry eyes, a feeling like my eye was just not all there and on top lots and lots of migraine like headaches.
I suffered an acute low-angle glaucoma attack, had to have major open eye surgery (2 flaps put in), have lost of 40% of vision in right eye (horizontal and verticial double vision). The opthomologist (sp?) I had been seeing for the last 3 years misdiagnosed it, said it was only migraines and stress.
I still have 1 1/2 week left taking prednosolone (a big nono with lyme) and then hopefully can start again. I am really worried about what is going to happen to my eyes and eye sight. The pain from the glaucoma attack was the worst I have every experienced.
If seeing an opthomologist, insist on having several different kinds of testing done. My glaucoma specialist was able to tell by feeling/pressing/touching my eye through my eyelid skin that the pressure was inaccurate and did a special test himeself. I was 40, way way too high (supposed to be around 12 - 15), had immediate surgery.
As to your grandson, yep the multi-colored circles I had for years, except nobody believed me.
I am sure the treatment plus supplies for healthy eyes will help him. I have been reading some reports about vasculitis and eye muscles, so taking something for muscles is good. Anyways, I hope you jackie o and nan's grandson get better.
Once I am back on abx, I will try to let everyone know my progress. My own computer is still acting up, so here I am at work after hours doing some online reading and just this one post.
Corinne
I do not have double vision, but there is no movement in the eyes, have to turn my head to look at objects. In addition: having optical neuritis; infection around the optic nerve, which puts pressure on it, creating blurry vision.
After on abx two years ago, vision and neuritis cleared up. Lyme came back this past summer and both conditions came back. Hopefully after treatment it will go away, however since my lyme went nuro, there could be some damage.
To keep the eyestrain down, wear sunglasses, it helps me!
Good luck
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Alex