My grandpa was color blind.  I remember when I first learned about this I was five or six years old and I was so confused what it meant.  He can’t see any colors I thought, that stinks!  My dad quickly corrected my misunderstanding explaining to me that grandpa could in fact see colors, he just couldn’t tell the difference between certain colors, and some colors he didn’t really see at all.  At the young age of five, I found that very confusing—I simply couldn’t understand what it would be like to live in a world full of brown grass.  I remember feeling quite sad for my grandpa, and took it upon myself to try to explain to him what different colors looked like—thank goodness he had a good sense of humor!  I often wondered if he would ever “get better.”

            Most of us are very much like my five- year-old self: we can’t imagine a world without the colors we are so used to seeing all around us.  So much so that some scientists have invented glasses that supposedly “fix” color-blindness.  I heard about these glasses recently and I became interested in them.  I was curious about how exactly they worked.  So, naturally, being the nerd that I am, I did a little research.  These magical glasses are called Enchroma glasses, and they are advertised with the slogan Color for the Color Blind.  The Enchroma glasses are meant to correct red-green colorblindness, which is the inability to distinguish between reds, greens, browns and oranges.  The glasses are quite expensive, costing anywhere from $400-$500.  I found the Enchroma website quite fascinating and well-designed.  I’ll link it here in case anyone is curious to learn more about the company, or the glasses themselves.

To better understand how the Enchroma glasses work, I think it helps to first have a general understanding of how color-blindness works.  As it turns out, colorblindness is not quite as simple as my dad made it out to be when I was five.  The National Eye Institute (NIH) explains that most people share a common “color vision sensory experience,” some people however, have color vision deficiencies, the most severe of these being colorblindness.  Essentially, people with color blindness do not distinguish between certain colors the way the rest of us do.  About 8% of men have colorblindness while only about .5% of women do.  This discrepancy is due to the fact that the gene responsible for colorblindness is on the X chromosome, and while female have two X chromosomes, males only have one (we all learned about dominant and recessive traits in like 8^th grade, need I explain more?).  For those of us who see color normally, what we are actually experiencing is a reflection of light.  Let me explain.  When light enters the eye, the cornea and the lens focus it onto the retina.  The retina contains light-sensitive cells called photoreceptors (rods or cones—literally called this because some are shaped like rods and some are shaped like cones..nice!).  Rods and cones both contain photopigments that basically undergo chemical changes when they absorb light.  Humans are trichromatic, meaning that we have three different types of photopigments.  Because the majority of us has the same set of cone photopigments, we share a similar visual experience (NIH).

So, what exactly is going on in someone with colorblindness?

Essentially, inherited colorblindness is caused by abnormal photopigments. It takes several different genes to make photopigments so if any of these genes has a defect it can lead to what we understand to be colorblindness.  Because there are several different kinds of cone cells, that each respond to different kinds of light (red, green, and blue), there are three different types of colorblindness.   Red-green colorblindness is the most common, followed by blue-yellow colorblindness.  It is quite rare to experience a complete loss of color vision.

So, back to the glasses.  As I mentioned earlier, the Enchroma glasses are meant to correct red-green colorblindness.  The Enchroma website does a very nice job of explaining how exactly their glasses work, so definitely check out their site, if you haven’t already.  To paraphrase: the lens of the glasses basically filters the light that enters the eye, which enhances certain colors.  This whole concept began as a computer simulation designed to simulate color vision deficiencies (read more here). The lenses on the  glasses not only cut out certain wavelengths of light, but they also separate the overlapping red and green cones so that the wearer is better able to detect both red and green. 

I think these glasses are really fascinating, but it does make me think about why exactly they need to exist.  Should we be seeing colorblindness as something that needs to be pathologized and therefore fixed, or more as a natural human difference to be embraced and accepted?  However you see it, there is no denying that people’s reactions to trying the glasses for the first time are pretty great!