"Here's a bit from an earlier article I wrote on sight fishing several years ago but still very much applies. (Excuse my Physics/optics background) "Here are a few tips on sunglasses for fishing. Of course get the best quality, UV blocking, etc etc. that you can afford.
Polarized Fishing Glasses work, Absolutely!!!
First, if there is glare, and there always is, they help a lot by reducing its blinding effect. Second, even without glare they selectively reduce other reflections from objects above water, including clouds and even the sky (the reflected sky gives most of its blue color to the sea). Finally, light coming from under water is slightly polarized in the vertical plane (polarized on transmission). The end effect is that the water seems darker and more transparent! But remember, it only works if you look at the water at some angle and not straight down.
Does it matter the time of the day?
Yes. Maximum polarization is obtained when the sun is at about 37 degrees from the horizon (in theory 100% polarization at the Brewster angle). If the sun is very low or very high the sunglasses will be of little help in filtering the glare in calm seas. A rule of thumb would be that polarized filters limit the glare from calm waters for a sun altitude between 30 and 60 degrees (but see next question). Anyway, it should be stressed that polarization won't help in looking directly at the sun (except in decreasing the overall intensity of everything by half). Coupling this with the tip above it pays to be on the water between around 9:30 to about 4:30 with a break around lunch. Keep the sun to your back as much as possible.
When the sea is ruffled the sun reflection becomes the familiar glitter, an elongated pattern of shimmering water stretching towards the sun. Because different parts of the glitter are reflected from different wave slopes, the degree of polarization varies from place to place. In those conditions the sunglasses will also help for high or low suns and the benefit will depend on where you are looking. As a side note, the width and length of the glitter together with the altitude of the sun can be used to compute the height of the waves without ever getting close to them!
Yellow or orange Provide less overall brightness protection, but excel in moderate-to-low level light conditions. They provide excellent depth perception, which makes them perfect as they enhance contrasts in tricky, flat-light and low light conditions. such as found in fishing and hunting.
Amber, rose or red Makes the world seem brighter. They provide excellent low-light visibility and enhance contrast (perfect for skiing and snowboarding in cloudy conditions). The vermillion, rose or red also enhance the visibility of objects against blue and green backgrounds, which makes them ideal for fishing grassy bottoms while amber lenses and brownish excells for sandy lake or stream beds).
Dark amber, copper or brown Blocks high amounts of blue light to heighten contrast and visual acuity. Particularly useful to improve contrast on grass and against blue skies. baseball, cycling, fishing (especially in waters with grassy bottoms) and against sand.
Gray Color-neutral, which means they cut down on overall brightness without distorting colors. These darker shades are intended primarily to cut through the glare and reduce eyestrain in moderate-to-bright conditions during all outdoor sports in bright light conditions.
Three kinds of light are associated with sunglasses: direct, reflected, and ambient. Direct light is light that goes straight from the light source (like the sun) to the eyes. Too much direct light can wash out details and even cause pain. Reflected light (glare) is light that has bounced off a reflective object to enter the eyes. Strong reflected light can be equally as damaging as direct light, such as light reflected from snow, water, glass, white sand and metal.
Ambient light is light that has bounced and scattered in many directions so that it is does not seem to have a specific source, such as the glow in the sky around a major city. Good sunglasses can compensate for all three forms of light.
So as you may have figured out, the color of the fish, the color of the bottom, the color of the surrounding foliage or background, the color of the sky and more all dictate the colors of your polarized lens. Iíve narrowed mine down to a pair of very light yellows for early and later, or low light conditions and a pair of brownish yellow for general sight fishing. I do carry a third pair at times for open water/very bright conditions and these are a dark neutral green/grey.
Lastly on optics, get good side shields and wear a hat or cap with a dark underbill so that your eyes are enclosed in a cocoon of dark. The last thing you need is reflections or light coming in from above, under or around your glasses."
Hope this helps!