I’m mildly red-green colorblind, as are around 8% of males, and far fewer females. The human eye typically has 3 types of color sensing cones which roughly correspond to blue, green, and red light. Colorblindness sets of these cones being “defective” or absent altogether, so the palette of colors visible to a colorblind person varies from person to person. The green and red cones have the most overlap, and so the most common type of colorblindness is red-green, which means the cones overlap more than they should.
According to the colorblindness test on the Enchroma website I am a “mild protan” which means the red cones in my eyes are shifted slightly towards the green cones. This results in darker reds starting to become indistinguishable from blacks and at the low-end of the green light my red cones firing too much.
I first read about Enchroma glasses a few years ago but because my colorblindness has never really presented me with a problem, I’m only made aware of it very rarely, the price at the time seemed prohibitive. But this year I got the itch to try them out. Enchroma has a 60 day money back guarantee as they don’t work for everyone (depending on the type of colorblindness you have), so earlier this year I ordered a pair.
I wasn’t expecting a huge effect from them, unlike some of the more dramatic videos online of some people’s first time experiences. And as my colorblindness was caused by my red cones being shifted I was expecting them to have the biggest effect on the range of reds I could distinguish.
The way the Enchroma glasses work is they filter out bands of light where the cones overlap the most, which blocks out a lot of the excessive overlap from the shifted cones. As they are just blocking out certain bands of light you’re not able to see more colors, but it helps your brain distinguish colors by removing a faulty signal.
The first time I tried on the glasses was during a pretty gloomy rainy afternoon (California had a historically wet winter) and the effect was, as I expected, pretty subtle. But what surprised me as that it wasn’t the reds that stood out more, but the greens. I first noticed this in the traffic lights, where the green light looked a lot greener than usual. I think what is happening is that because my red cones are shifted towards the green, by blocking out the overlapping band of red the greens start to look a lot more pure and, well, green.
I’ve had them for about two months now and worn them on my regular (bicycle) commute, out and about, and hiking. The effect when out hiking is easiest notice, especially this time of year in California when everything is temporarily green during the Spring. If I wear the glasses all day and then lift them off I can see the reds start to seep into grass that was previously green, and without them the greens all seem duller.
The glasses are not cheap, but, seeing as being out in the California sun glasses are necessary anyway, I’m pretty happy with a small upgrade to my color vision, particularly when out and about in the green landscapes.