Green Enhances vision

Sometimes applying a color filter helps us detect details in an image. Somewhere along the way I noticed this was especially true when I applied a green filter to images. Small things just seemed to be much easier to spot. A string, facial hair, slight changes in texture seemed to suddenly pop out from an otherwise normal looking image. I wondered if it was just me, because I always wonder how weird I actually am. It turns out that as weird as I might be, in this instance, I am pretty normal.

Human eyes translate light into colors. The human retina identifies colors between 400 and 700 nanometers, with blue at the lowest and red at the highest end of the color spectrum.

 The color green, which is a mixture of blue and yellow, is located at about 550 nanometers, making it the easiest for the retina to perceive. Since green is near the middle of the color spectrum, it enhances the blue and red colors at the opposite ends, making them easier to see.

We perceive more shades of green than any other color. But why green? Shouldn’t we be able to see all colors equally? On a purely scientific level, our vision gives green more weight because two out of the three types of cones in our retinas—medium and long cones—are most sensitive to the part of the spectrum of light that we perceive as green. Short cones favor the blue end of the spectrum, but the other two overlap in the middle, which is the sweet spot for all things green.

But basic biology aside, is there a reason that our eyes evolved this way? There’s more interpretive debate here, but most scientists agree that it’s because we evolved in predominantly green environments like forests and jungles where, Darwin would argue, our ancestors who could perceive more shades of green were better equipped to distinguish the tastiest food sources (as primates, humans are biologically geared Before you get too impressed with yourself, you should know that the mantis shrimp has twelve types of photoreceptors (versus humans’ three), which allow them to perceive a wider slice of the light spectrum.

Check out this Youtube video to see what I mean: https://bit.ly/37jwXBp