I'm surprised nobody has mentioned the problem with this study is it is not blind.
Clearly the sleeper knows if they are wearing an eye mask with holes that let in light, or if they are wearing a complete eye mask.
I work in the neurotech/sleeptech space, and it should be possible to do this study in a double blind method.
In a sleep lab, with EEG, monitor the users sleep state. When they are in any non-wake state ambient light could be brought into the room. In one instance, no light is applied, in another light is applied.
Don't use the usual camera's that are used in a sleep lab. In such a method the trial is double blind, but also much more expensive than the method used.
Clearly the sleeper knows if they are wearing an eye mask with holes that let in light, or if they are wearing a complete eye mask.
I work in the neurotech/sleeptech space, and it should be possible to do this study in a double blind method.
In a sleep lab, with EEG, monitor the users sleep state. When they are in any non-wake state ambient light could be brought into the room. In one instance, no light is applied, in another light is applied. Don't use the usual camera's that are used in a sleep lab. In such a method the trial is double blind, but also much more expensive than the method used.