I am worried that my eyesight might decay from looking at a computer monitor for hours on end.
do you guys have any tips on reducing eye strain and having overall healthy eyes?
and are certain monitors better at reducing eye strain than others?
TL;DR - your eyesight does not decay from being used. There are other reasons why it's a really good idea to reduce eyestrain as much as possible.
An Interesting Topic.
Eyesight has two basic components that affect the visual perception: Optics and sensors. Optically, as long as the cornea refracts the light within acceptable limits for the lens to fine-tune the focus so that the image projected on the retina is sharp, everything is fine and you cannot really destroy this with using your eyes. Sure, prolonged periods of looking very close can stress the muscles that operate the lens, but basically the optics of eye do not suffer from looking at computers, books or whatever. With age, the ability of the lens to adjust will decline, resulting in reduced area of ability to sharpen your vision to. Since normally eye should be focused to infinity when lens is relaxed (looking far), the result is that the ability to look very close will slowly deteriorate with age. This happens to everyone to varying extent, similar to how we lose the ability to hear very high-pitched sounds.
Optically bad eyesight is usually caused by eyeballs being slightly deformed so that the retina is out of focus and the lens can't compensate - most common is the eyeballs being too long, in which case the focus is ahead of the retina when the lens is relaxed, reducing the ability to see far. Opposite case is called farsightedness and it reduces theability to focus on objects at close distances. None of these are affected in the slightest by usage of the eyes; it depends on how your eyes grow up to be. Some more complex stuff includes cylindrical
Also, eyesight can deteriorate optically by diseases like cataracts, but those do not result from looking at computer screens.
The sensory components of eyesight are the retinas, eye nerves and visual cortex that processes the image to comprehensible data. None of these are significantly affected by usage. The only thing I could think of is that static, large contrast images tend to generate short-lived afterimages, but they fade so fast that it makes no difference. Obviously staying in dark room staring at a computer screen will make your eyes more slightly more sensitive to light, at least on short term, but that's about it as far as I know. The amount of cells on the retina's yellow spot pretty much dictates the aquity of your eyesight as long as the optics are OK, either naturally or corrected by glasses/contacts.
So, none of the components that your eyesight consists of will decay due to looking at computers. However, looking at computers all day will probably have other adverse effects. Mainly that looking close all the time and also looking at much the same direction causes stress on the muscles that adjust the lens, as well as the muscles that move the eyes. And your eyes can dry, since working on computers tends to reduce blinking frequency. Not to mention things like neck or back muscles getting sore... These factors don't really affect your eyesight or visual aquity, but they will make you feel like crap, have headaches or even migraines, feel more tired than you actually are, and even making you feel like your eyesight gets worse.
Now... there's already a lot of things that have been said that can prevent and reduce eyestrain. The most important one is to have breaks when you look at something else than the screen, prefereably at a distance, and move your eyes around.
Secondly, make sure that the lighting in the room is at suitable level and uses indirect lighting as much as possible. Indirect means that the light is diffused before it gets into your eyes, either by reflecting from matt surfaces (walls) or by going through a diffuser around/below the lamp. Direct light means raw light coming from the lightbulb/tube or reflecting from computer screen or other shiny stuff in your room. Too bright lighting, and the screen will look too dark and contrast becomes more difficult to discern; basically the more contrast your monitor can offer, the brighter the lighting can be in the room before it starts to disturb. Too dark lighting, and your eyes will try to adapt to darkness and be disrupted by the bright areas on the screen; when your pupils dilate, you also lose some depth accuracy from the refraction and things can start to look more fuzzy (which is one of the reasons people see better at bright than dim lighting, just like cameras...).
Thirdly, configure your monitor so that it's good to look at. This involves both position and calibration. Position should be anything from 70 to 100 cm away from your eyes, though preferences vary. Also, the upper edge of the screen should be about level with your eyes when you're sitting comfortably. As far as screen calibration goes, it's a good rule of thumb to always use as much contrast as possible, then adjust the colours and brightness with gamma for each channels; this will allow you to us the full capacities of your monitor as far as colourspace goes, and full range of colours is usually better to look at than limiting the screen with reduced contrast. If some parts of the image are too bright, either reduce brightness or increase the lighting in your room; in most cases "too bright" is caused by the eyes being accommodated to darkness so of course it'll cause problems. Some CRT's start to develope blooming habits though, so use common sense with the adjustments... although with current trends in gaming, an auto-blooming screen might be pretty awesome.

Of course you should use as high a resolution as possible, but make sure that characters stay easily recognizeable and readable from your viewing distance. High resolution reduces the aliasing effects and makes things in general more pleasant... and with flat screens you should always, always use the native resolution of the screen because upscaling lower resolutions will often cause problems. Some screens handle it better than others.
Also, it is advisable to always use as high a vertical frequency as possible... at least when gaming. When working, just use sufficient vertical retrace frequency that the CRT monitor doesn't visibly blink when you look at it with the side of your vision... Some people claim that since human eyes can see something like 28 frames per second (which I consider bull**** of the highest degree anyway), it won't make a difference, but I beg to differ; 60Hz is well within human perception of frequency. That's because even if the yellow spot of retinas and the visual cortex is hypothetically wired to handle about 30 "frames" per a second, the cells otherwhere in the retina sense brightness instead of colour and have much higher sensitivity for motion, which is why you will often notice things like fluorescent lamps - or even traditional light bulbs occasionally - to blink due to the frequency of the alternating current if you look at them with the side of your vision. And of course anyone can usually sense the difference between 120 frames per second and 60 frames per second in games played on a CRT, even despite the limitations of the colour vision of eyes, because human visual cortex is really good at extrapolating between the "frames" that the eyes register - that's why our world looks continuous and not a slideshow. Good example is a flying tennis ball - eyes focus onto the flying ball only once or twice, then the brains fill in the trajectory and tell us that it flied from A to B and it looks continuous to us. Same with games, except that the missing frames will often be detected - try playing at 30 FPS and things will look a lot less continuous than it theoretically should be.
But I digress... and I don't think I have much more to say on the matter at hand anyway.