Thank you for sharing your experience in such detail. First, I would like you to know that your symptoms are not related to your neck and back pain. The nerves that supply the eyes are in a completely different location from those that supply the neck and back. In fact, the nerves that supply the eyes do not even course through the spinal cord. They come directly from the brain.
Your symptoms may be due to a couple of conditions. The most likely possibility is a condition termed ocular migranes. Ocular migranes manifests themselves as sudden changes in vision. These can take the form of sudden blurrying of the vision, flashing lights, wavy lines, etc... These may be followed by headache but often are not. They also may disappear just as easily as they began.
Another less likely possibility, but one that must be strongly considered is amaurosis fugax
. In amaurosis fugax, there is a temporary loss of circulation to the eye. This can frequently be caused by cholesterol particles (termed cholesterol emboli) that become temporarily lodged in the blood vessels that supply the eye. In amaurosis fugax, the cholestrol emboli will dissolve or pass through the blood vessels and the event is resolved. Usually the event last a few minutes, although it mostly causes a complete loss of vision during the event. It is important to check for this condition because it could be a sign of an impending permanent blockage of a blood vessel and ultimately affect the vision permanently.
In order to differentiate between the above conditions or to discover any other possibilities, you should be under the management of a neurologist and an ophthalmologist
. I would recommend that you first visit a neurologist as they are primary doctors and can oversee all the blood work, imaging tests and consultations needed for accurate diagnosis and management. The neurologist will probably ask for a complete eye exam from an ophthalmologist. Frankly, I expect this eye exam to be normal.
I think it is important that you have an evaluation at your earliest convinience, but I do not want you to become overly concerned. I do believe that the most likely possibility is ocular migranes. If this is in fact the diagnosis, it is not a dangerous condition; although, as you have experienced, quite scary.
I hope this is helpful and I wish you the best of luck as you look for some answers...