I also sleep better on days when I wear my glasses (which have a blue blocking coating) as compared to my contacts. Unfortunately the contacts provide better vision, thanks to my astigmatism.
It doesn't. But my contacts correct for my astigmatism much better than my glasses do (which may or may not have any astigmatism correction, I'm not sure). So the vision I get out of my contacts is sharper than my glasses, but my glasses offer blue blocking. Tradeoffs.