Too much of LCD can be harmful to your eyes. If you turned the brightness of the LCD as high as it went and stared at the screen for a long time, your eyes must be uncomfortable. The human eye's comfort level is at 40 cd/m^2, but LCD's go up to and above in some cases 300cd/m^2. Thus, it is better for you to watch less TV.
As we all know that too much of anything is too harmful for us. If you see the LCD TV with the high lightness, I am pretty sure that the screen will not be good for your eyes. We all know that when you focus on the LCD TV for too long, which will make your eyes feel tired then you are likely to get the bloodshot. Besides, the TV will display the images on condition that the LCD screens have to flicker and release some waves; both of them are harmful to our eyes. At the age of the LCD, many people are getting used to the LCD, in spite of the harm of LCD screen. However, compared with the CRT screen, the LCD screen is much better than the CRT, because as we all know the society is developing and everything is updating and processing so that the pros can make the LCD screens flicker less and release less harmful waves.
Well, it seems that you are quite concerned about your vision health. So, as far as I know, any electronic devices available will generate different levels of damage to your eyes because there is always harmful radiation. Although LCD is quite advanced in giving out less harmful lights, it is still harmful to you. So, what we need to bear in mind is to watch less TV and take breaks from time to time.