There must be others out there who like me who have some poultry genes in their makeup. Folks who find that any amount of ambient light interferes with getting to, or staying sleep, and that growing daylight soon leads to a full awakening, if not crowing and clucking.
The genesis of my cure for this problem comes from a few occasions of staying in Las Vegas hotels with total blackout curtains in the bedrooms.
I found that with a room totally dark I could sleep way longer, and well into the unseen daylight as compared to any other sleeping situation. My first experimentation with this sleep aid was in tent camping, where any daylight is immediately evident. In camping, I just covered my eyes with the darkest cloth object I could find. Works pretty well, except for the breathing part. It's tough to cover your eyes well and not cover your nose too, and to start breathing stale air and at least imagining a CO2 buildup happening in your system.
At this point you may be thinking "just use a sleep mask, that's what they're made for". Well that true, and they can work pretty well, but not if you are wearing a CPAP mask and headgear. So, my simple solution to this "Chicken Complex" (medical term) issue is to keep a dark hand towel near my pillow. If I start to wake up with the sun, but prefer not to, I simply lay the towel over my face and doze on. The prior problem of re-breathing one's own exhalations is handily solved by the CPAP providing a constant flow of fresh air from a remote location. I also find the hand towel a much more comfortable and functional solution to the light problem as compared to prior experiences with a sleep mask. The only drawback to this solution is that if anyone unfamiliar with your sleeping habits happens to come upon your sleeping form they may think you have died.
Heck, people who don't even need CPAPs may want to switch just so they can sleep better, with a towel over their face and still breath fresh air. A plus for PAPers. Ain't we lucky?
For what it's worth,