Yes they do emit radiation, otherwise it wouldn't be so tough to read long texts on LCD screens.
Don't believe me? Put a piece of newspaper next to your LCD screen and read both of them for a while, you will notice that by reading newspaper your eyes don't get tired that insanely fast by reading PC screen.
AND other aspect is that, LCD (actually all type of monitors) emit these waves of radiation that affect your face skin, trust me, I've spent alot of time in front of computer monitors and my skin isn't that good as it should be.
Computer manufacturers should find a new technology to use for building pc screens, otherwise it will remain harmful to human skin and overall health.