Have you ever had a sleep study done?
Yes, and it showed Very Bad central sleep apnea (brain forgets to tell lungs to breathe while you sleep) and CPAP machine didn’t help with the wake up issues.
I have acquired nystagmus from the head injury and their best guess is too much adrenaline is being released as part of the waking up process.
It DOESNT happen if I get startled awake. Has to be a natural wake up to feel it.