You can use it as a monitor - assuming your TV and GPU has the right ports to connect. However, Both TVs and Monitors can and will degrade your eyes to some degree during extended uses and/or if you sit too close to your monitor. My suggestion is so sit at least 1.2x the length of your monitor - 19" x 1.3 = 22.8inches. This is my personal "rule" and it only applies to monitors. Which is why you may want to sit slightly further away when your watching movies - roughly 1.8x when you watch movies - this is also good b/c you'll probably be snacking during movies, never hurts to keep food further away from your keyboard and mouse.
~Coffee