The neck pain may be caused by the cervical spondylosis, lymph node enlargement and muscle damage. If you sit too long time before the computer, the muscles must not be adjusted appropriately which may indirectly affect your eye nerves. That is why your eyes may feel blurry and can't see clearly after a long time work. You'd better rest for a while for your eyes and neck.
Well, it seems that you have got neckache and blurred vision in the same time. And perhaps you have been using computer for too much time. So, I mean, your nechache and blurred vision are both resulted from using computer. Generally speaking, nechache will not affect your vision, it is true. Maybe you have attributed vision problem to nechache, but the truth is not that you know? And my advice for you is to take enough time to rest and reduce the time in front of the computer.