Neck problems do not necessarily include neck pain. The muscle tightness is the symptom of the underlying problem in may cases.

It sounds as if the neuro and his assistants ( Physician Assistants I hope) did minimal diagnostics. Not uncommon for a whiplash/concussion injury.

In your case, it sounds like a CT or MRI/MRA may be worthwhile. Since the visual cortex is near the point of impact, maybe there is damage they can image such a vascular issues. Some narrowing of blood vessels could be causing problems. This can be caused by inflammation in the area of impact.

Do your pupils react properly? This should have been one of the first tests done by the ER, PCP and neurologist.

I hope the driver that hit you has good insurance and you have a good mTBI attorney. Sounds like you are in for a longer than usual recovery, as if there is any usual time line. Just that the longer it takes to recover, the greater the chance of less recovery.

Has the neuro suggested a VEP? This is a Visual Evoked Potentials test done with EEG equipment. It measure how the brain is reacting to visual stimuli. A full qEEG test with VEP and AEP sounds worthwhile. For this, it is good to find a specialist in qEEG testing.

If you tell me what area you live in, I can do some research to find an experienced qEEG clinic.

My best to you.