Why do we see Colors???

So the other day, I was out on a shopping spree, digging for just the perfect outfit for myself out of a gigantic pile of clothes. After hours of searching relentlessly, I finally narrowed down on a pink dress. The mirror probably thought, “Nope! Not this colour, lady!” Yes, that’s right. That colour definitely didn’t suit me. Disappointed, I replaced the dress back to the shelf it belonged to and headed home straightway. What a morose day! But hey, as I was walking down the lane, a sudden thought struck me like a lightning bolt. Our life revolves so much around colors, but what is it that makes us see these colors? Why and how are we able to see colors?  This thought kept eating me up all throughout the journey home. As soon as I reached home, I quickly started researching more about it. Let me share it with you.

                First of all, there is nothing like a “color” as such in physics! All my artistic friends would probably be exasperated at this statement, but yes, that’s true. What we see are just qualities of light being reflected or bounced off from a surface. Light basically comprises of a broad spectrum of wavelengths. When light falls on an object, some part is absorbed whereas some part is reflected. Whatever part of light is scattered is then seen, as what we call “a color”, by us. Going by that, a red apple isn’t “red” afterall! It simply reflects red light and absorbs other whose resultant effect makes us see the “redness” in the apple. Wow! That’s a great revelation, ain’t it? Well, lot’s more coming up. Read on..

So, the Human eye consists of two special cells called the ‘Rods’ and the ‘Cones’. These are better known as ‘Photoreceptors’ since they deal with vision. Now, the Rods, which are huge in numbers (120 million), don’t really help so much in identifying colors. They are sensitive to dim light and help our eyes to adjust when we enter a darkened room. The Cones, on the other hand, are very sensitive to bright light, most specifically to the three primary colors: Red, Green and Blue.  There are around 6 million Cones in a human eye.

 Let’s consider the procedure of perceiving the color of an apple. As I have mentioned earlier, the apple will absorb some part of the sun’s incident white light and reflect the remaining wavelengths. Now, when this reflected red light hits the Cones, it stimulates them to varying degrees. Signals are then sent from the Cones to the brain, which in turn, acts as a translator and translates these signals into the perception of color. So the brain prompts to us “RED! RED! RED!” Ok. Not really this way. But you do get the point, don’t you?

There might be some people who have weaker Cones or probably do not have a Cone of a particular type. Such people face difficulty in perceiving certain colors and are called “Color Blind”.

That leads me to think, there is probably someone out there who bought the very same dress I rejected because she could not perceive the pink color and thought it to be a black one instead.  Aah! This enigmatic world! Never ceases to amaze me J

Rebecca Correia