We did two things- Walmart has a static cling kind of tint that works really good- relatively cheap too and then there is a reflective silver bubble from camping world that worke good to completely darken the windows.
You do know that the night sky is not bright, don't you? After about 10 or so, it is actually a twilight that gradually darkens then gets lighter in the wee morning hours. We did not do anything special to the windows and slept just fine.
Most people can take a mid afternoon nap in the daylight and not have any problems with sleep. As Hook said, just close your eyes and it will be dark inside. LOL Most people in the summer time get off their regular schedule and sleep when they need to do so.
The 25 years + that I lived in rural Alaska, I never was concerned with the summer light. I would sleep when I was sleepy, eat when hungry and do what I wanted to do, anytime of the day. Put your watch in a drawer, and enjoy the north country while there, you can sleep when you get back home. LOL Duct tape over the eyes would probably work as well, might remove the eyelashes and brows when removed though. Summer time bush flying was better at night, IMHO due to smoother air, less traffic, more wildlife out and about. Daytime heat thermals could make for a bumpy ride in a Super Cub.
For most people, just closing the RV shades should work I would think. Spray paint the skylight over the bed, if there is one.
One night when we were living in Nenana, Alaska, my wife woke me up concerned about some noise she heard outside. It was about 3 AM and when I opened the front door, I found both our daughter, ages 4 and 6 playing on the deck and in their playhouse. They had gotten dressed and gone out to play. Hard to fuss at them for this but my wife thought they should come in the house and go back to bed. LOL
Formerly of Colorado and Alaska
2011 Chevy 3500 DRW Dmax CC 4X4- Rockwood 8281 SS 5th Whl & 2008 Lance 845 TC www.pajbcooper.com web site
Alaska-Colorado and other Trips posted
"Without challenge, adventure is impossible".