Involuntary, rapid eye movements. are these concussion related?

Yes they can be: Un equal input from the balance organs in the inner ears can produce nystagmus (eye movements) with occiopsia (what ones sees with these eye movements ) and vertigo (the sensation of being pulled or turned in a direction) . The problem can be withe inner ear itself or the connections to the brain (8th craniel nerve) or damaged structures within the brain. Medications can also cause this problem.