The blurry vision after the neck massage may be normal and temporary. It is the fluctuation of the eye nerves that causes the blurry vision. You should just take the great relax and good rest for the eyes. Then your blurry vision may get recovery. There is no worry for you. You could also use some eye drops to release the symptom.
I am not sure if this normal. But it is not a big problem. I have the same experience with you. And the massage told me that just stand up and drink some water, also have a small snack. I do this as he told me, then, i feel better. If you feel vision blurry right now, maybe you can try this. Hope it can help you.
From what I know, there is little connection between your neck and your vision. So, you wouldn't have any blurred vision because of neck massage. Perhaps in the meantime there is something wrong that has got something to do with your vision. Just try to figure it out and pay attention to your eye health.