Walk through any well-stocked tackle store these days and it's a sure bet that somewhere onsite you'll find a display rack with a range of polarized sunglasses for fishing. Some of the glasses on display will be cheap and cheerful, while others can cost several hundred dollars.

There are plenty of reasons for wearing quality sunglasses any time you're outdoors. Polarized sunglasses filter out ultra-violet (UV) rays, while providing a physical shield to keep foreign objects from finding their way into your eyes. They also provide protection against overly-intense sunlight, relieving eyestrain and pounding headaches. But perhaps the most-talked-about benefit is that polarized lenses that let you see through the water's surface and spot cover, weedlines and fish. That makes them especially valuable at this time of year, whether you're stream fishing for trout or steelhead, or prowling shallow water looking for fresh weed growth that will attract panfish, walleye and pike.

Obviously some sunglasses do all this better than others do, and that's a big reason for the wide price difference. With all due respect to ZZ Top, you have to really watch it with those cheap sunglasses, because some of them can do more harm than good.

Lenses come in two basic materials - glass and plastics. Glass still provides the best optical quality, the trade-off being that they're generally heavier and more expensive. Good plastic lenses are almost as optically-correct as glass, and they're more resistant to fogging. The only real downside to plastic lenses is that they're easier to scratch.

Whatever you choose, look for precision-ground lenses as opposed to cheap molded ones, which are often full of distortion. You can get a good idea of what you're buying by holding the glasses a foot or so in front of you, then looking through the lenses at a small target while slowly moving the glasses around. If your target begins to move or change shape like it's in a Fun House mirror, that's a pretty clear indication that the lenses contains enough distortion to give you a headache. Skip those ones and try some others.

Quality sunglasses come in a variety of colors to suit different light conditions. Green or gray lenses are the most popular among anglers because these tints do not affect color perception. Yellow or amber lenses make it look brighter out than it really is, making them ideal for use early and late in the day. Yellow is also good when fishing on dull, overcast days, or in the rain.

Of course, good lenses are nothing without good frames, and there's more to that than just cosmetics and individual taste. Some frames, for example, feature side blinders or wrap-around temple arms to keep stray light from entering at the sides. Plastic frames are as lightweight as traditional wire, but tend to be more comfortable in cold weather. Flexible frames that can withstand being sat on are usually worth the extra cost. As with anything else, you get what you pay for. But you can't put a price tag on your sight, so investing in good fishing glasses makes a whole lot of sense any way you look at it.