ryans I've only been playing it docked with my old trusty 40" Samsung LCD from 2008. The initial setup is done on the handheld itself though, and I would have known whether I had trouble with it because I would have had aching eyes and felt seasick within seconds/minutes of looking at it like what normally happens with most LED computer monitors. Maybe the handheld screen is backlit by CCFL on the Switch handheld? I'm not sure, but let's just say it was a positive surprise (for once!)
On the Wikipedia article for the Nintendo Switch, it states this about this display:
Display
6.2-inch, 1280 × 720p LCD (237 ppi)
Up to 1080p via HDMI while docked