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How Brown Sunglass Lenses Work

Updated: Jul 19, 2023

When it comes to sunglasses, no lens is more versatile than a brown tint. The reason for this, and why brown lenses can colorize your view in a way few other lenses can do, is very interesting for a simple reason: In terms of colors, brown is not a color on the visible light spectrum and even if it was, our eyes do not have specific any receptors to pick up the color.

Source: @randolphusa

Instead, brown is a mix of red and green, but mostly red, making a dark orange color. It can also have some blue mixed in, but essentially it is red with green. Though there can be many different concentrations and variations of brown lenses, this is the essential recipe.

This is important because we have three kinds of color receptors in our eyes that can pick up different light wavelengths and generally they correspond to blue, green, and red, which you can read more about here (LINK).

The basic science of tinted lenses is that the lens transmits relatively more of the lens color and absorbs more of the opposite color. A green lens will let more green light through the lens relative to other colors (and block more magenta) so the visual experience will look more green. You can see this on the color wheel for green.

Source: Canva

In the case of a brown lens, red is transmitted the most and becomes richer, with green also being let through at lower levels than red, and blue being the most absorbed and least transmitted.

A brown lens will therefore let more red and green light though the lens relative to blue. This is notable because when it comes to contrast and clarity, red and green are very useful and blue is not, so brown checks a lot of boxes.

Red is the most useful in regard to color and contrast enhancement because there is less of it. Since red wavelengths have the largest waves and the lowest energy, they get absorbed easier by most objects relative to green and blue. Since they are absorbed more, they do not reflect off objects to create a red appearance. Look around outside, how much red do you see relative to blue and green? In many places, like where I live in the northeast, it's almost all blue and green.

But in order to create contrast, and by extension a bit more clarity, we need to be able to use all the colors at our disposal. If you are on a golf course, and the grass and surrounding trees are all green, how can you sharply tell the greens apart if they are all so similar?

By using red, which is actually present in almost everything you can see. All colored objects have the appearance of the color wavelength the object reflects. But it is very rare for an object to only reflect one particular wavelength. Usually, there is a mix of wavelengths and the object has combination of colors that span the light spectrum, and each combination makes a different specific color.

For example, see the differences between red, green, and yellow apples.

Source: Mark N. Merzlyak

The red apple has a lot of red light (roughly 600-700) but still has some blue (400-500) and a bit of green (500-600). The green apple has a lot of green but has a lot of red and a bit of blue too. The yellow is a mix of red and green, with a bit of blue.

So a green apple absorbs a lot of red light but does reflect some of it. What if we were to alter the amount of green and red there was relative to their starting positions, but only slightly?

We would get a redder apple, but it would be a redder green. That might sound unappealing, but it's actually very subtle. See this:

Letting more red reflect from a green apple relative to the green light makes the apple look more yellow (but still green) similar to how a yellow apple is nearly equal parts red and green.

If there were a basket full of green apples, green peppers, watermelon, and green pears, on a bright day it might be hard to tell the different items apart because the green is so bright. Boosting red relative to green will bring out the subtle differences in each object since they all have different spectral properties.

See how this plays out in this (very accurate) Oakley simulation of their bronze-based Prizm lens.

There is another reason brown lenses have enhanced color and clarity, and that is the relative reduction of blue light.

Blue light has two problems with it in regards to optics: there is too much of it and it blurs other colors (it has other problems in regards to health). Because blue light has the highest amount of energy and the shortest wavelength, it is absorbed the least of any color. That is why the sky and bodies of water are blue, and there is a lot of blue all around us.

Source: SportRX

Short-wave (near 400nm) high-energy blue light creates scatter and haze, making objects appear somewhat blurry. See that Oakley picture above. The left side looks much more blue, and duller, compared to the right side.

Brown lenses are well placed to reduce blue light because of the mix of red and green faces opposite blue on the color wheel, as seen above.

For the issue of blue being so common, brown lenses are great. For the haze, brown lenses are only moderately effective as they do not block all of the high-energy light, just more of it. Many brands offer high-energy blue light blocking as a feature, and these brands have managed to completely eliminate it. Maui Jim, Serengeti, Costa, Spy, and Bajio are just some examples.

Now that we have established what brown lenses do, let's understand some aspects of them.

The color wheel can be divided into warm and cool colors. The warmth or coolness of a color is also known as its color temperature. The color combinations found on a color wheel often have a balance of warm and cool colors. According to color psychology, different color temperatures evoke different feelings. For example, warm colors evoke feelings of comfort and vitality, while cool colors are associated with tranquility and seclusion.

Warm hues span from red to yellow and evoke a sense of warmth akin to the sun.

Cool shades encompass blue, green, and purple, evoking a coolness reminiscent of water.

Brown is on the warm side of the wheel and as such, will make your view feel "hotter" and can cause you to feel more energized and excited. This is often why brown lenses can feel overwhelming in the most bright light on the hottest days. It isn't that too might light is coming through the lens. It's that you feel the world is too overwhelmingly "hot". When I was in Phoenix in 115-degree weather (45 Celsius), I exclusively wore grey and green lenses. The brown was too much (especially in an environment like the desert with a lot of red).

That being said, where I live in the northeast I wear brown lenses more than any other lens colors combined. They work in full sun since they are a dense tint. They work in cloudy conditions where the world gets an extra blue filter from the clouds and the brown lenses brighten and colorize everything. They work for sports with their contrast-enhancing features.

Here is an example of Maui Jim's HCL Bronze Lens

Here is Serengeti's Drivers Lens

You can see both of them do an excellent job at cutting down any blue haze and boosting reds and greens to enhance the colors of all objects.

If I had to pick only one lens to keep for the rest of my life it would be a tough choice between the Maui Jim bronze and the Serengeti Driver. I also really enjoy the Costa Del Mar Green Mirror bronze lens, the Persol Brown lens, Oakley Prizm Tungsten and Ruby, Randolph American Tan, and Revo Terra.

There's a lot more to say about brown lenses and their applications which I discuss here, here, and here. Let me know what your experience with brown lenses is like.


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