In general, yes, LCD's are better on the eyes then a standard CRT. LCD's do not continually refresh the screens like CRT's causing that flicker (hrz refresh rate). Some people are more sensitive to refresh flicker then others. The worst case scenario is photosensitive epilepsy. Most cases its people working long hours under flourescent lights, low monitor refresh rates, and high resolutions for small screen type and graphics. LCD's are also getting better and better especially in regards to contrast ratios and brightness, but CRT's are also improving alot as well. None of that really matters though if its not set to perform well. I see alot of people working under the windows base default, 65hz refresh.
Some things to do to help prevent eye strain.
-Set the refresh rate on your monitor to over 75hz. Preferably 85hz or higher.
-Set the contrast high then play with the brightness/gamma to an acceptable level.
-Set the resolution within a tolerable setting that doesn't require a microscope to read text. Some people like to put a 17" monitor at 1280x1024 and they wonder why their eyes hurt when they squint to read everything. Scale the desktop resolution according to th size of the monitor. A 1280x1024 may work on a 21" monitor, but its a helluva eye strain on a 17".*
-Try to work under a incandescent light rather then a flourescent. If you have flourescent lighting in the office and can't help that, support it with a desktop incandescent lamp.
-Make sure the monitor is set to eye level, not looking down or up. ALso not set too close to you. At least 18"s away.
-Pinch the geometry in to decrease the distortion. The default is 1/4-1/2" in from the border for a reason. I know we all love to expand the screen to its max but that area tends to have alot of distortion. I work in graphic design and we love to get every possible inch out of the screen and our tools are always off in the edges.
-Keep electromagnetic fields away from the monitors, especially CRT. Something like a power supply or tranformer (wall socket) should be kept away from the monitor. Speakers should be kept at a small distance too since the magnets in the speakers can cause distortion as well. Sub woofers are especially strong. EM fields can severly distort your screen and cause color distortion and wavy lines.
*Mac OS X's Quartz technology uses a antialiased dispay to draw its windows. I believe that it draws its window in nearly a vector style format. This means that you should see very clear text and graphics that can scale at an infinite rate. Supposedly the pages are like PDF pages. I would have to check on this. Somethig like this is the base for the new age of on screen display. Vector graphics would mean that you could set your resolution to a tight 1600x1200 on a 17" monitor yet all of the text and icons would still appear large and clear.
Anyways. If you are looking for a LCD monitor remember that they do not refresh in the way a CRT does. This is beneficial and negative. Its beneficial to your eyes yet negative to certain application which require a fast clean redraw. Most relevant are games. You can sometimes get ghosting, and chunky redraws with LCD's but its not as bad as older LCD's used to be. This should not 3D work too bad, at least none of the 3D animators I know complained about it. Big factors to keep in mind are brightness: Try to get over 250, preferable 300+. Contrast ratio should be as high as possible too: 400:1 or higher. Also make sure it has a decent view angle. Tight view angles distort alot when you are not directly in front of the screen. As you may have seen in laptops, if you move your head to the side you will see that tinting in the screen. Wider view angles allow for better viewing. Go for 140 degrees+ horizontal, 110+ degrees vertical. Make sure the monitor is a multisync and will allow for different resolution switches. Most do nowadays.
A veery important thing to check after yu have purchased the monitor is to check for dead pixels. Most factories will allow for 3-8 or so and still ship. Check with the retailer on their policy about dead pixels and what the minimum count is for a valid return/replacement. There are utilities that check for dead pixels. They are not a major problem but when you have more then 10, it can be quite bothersome to see these dead dots on the screen. Most places allow for a return when you have 10 or more dead pixels.
Hope this helps you on the technology end. Still, monitor or not, you should see your doctor/optomotrist and tell them your situation. They may recommend special computer eye glasses to help relieve strain or you may even need normal glasses. You should also take breaks often. I typically take a 30 second break whenever I can (maybe every 30 minutes) and look at other things that are different focal ranges (look out th window, etc), stretch a bit, etc. Every 2 hours or so I try to take a short walk around the office or something. Helps when you are staring at a computer screen 10+ hours a day.
good luck