There are ways to set it up with an alternate/sham treatment for the control group (maybe some nice pictures to hang on the wall--something equally decorative b

There are ways to set it up with an alternate/sham treatment for the control group (maybe some nice pictures to hang on the wall--something equally decorative but not light-blocking). It's not perfect because there's no way to make it fully blinded, but the results would still be a substantial improvement over the existing observational study discussed in the article here.