It's not uncommon for deaf people to use sign language in their sleep. Those born blind experience dreams involving things such as emotion, sound and smell rather than sight. Check 20 more interesting facts you didn’t know about sleep here.
Avoid caffeine within 8-10 hours of bedtime, and viewing bright light, especially bright overhead lights between 10 pm and 4 am. Together with early morning sunlight exposure - remember from One-a-week #20 - on sunlight? - these three simple to implement lifestyle hacks will massively improve the quality of your nighttime rest.
“Sleep is THE foundation of our mental and physical health and performance in all endeavors. Yet no one is perfect about sleep. The occasional night out or missing sunlight viewing here and there is not a big deal, so don’t obsess about that. However, if any of us drift from these and the other behaviors for too long, we start to suffer. So whatever your life and goals and schedule, master your sleep. You’ll be so happy you did!”
Dr. Andrew Huberman on the Huberman Lab Podcast Neural Network - Toolkit for Sleep