Living with colour deficient vision

"OMG, so you go at red lights?" 

That's invariably the most common reaction to my revelation that I have red-green colour deficient vision. I'm mostly amused, and I start to explain that it's a little more complicated than that - I can differentiate some reds and greens quite easily, but not certain other shades of reds and greens. Let me attempt to regale you with facts about what I see (or do not see!).

What is a colour deficiency? Is it the same as 'colour blindness'?

Typographic doodles.. in black & white..

The American Optometric Association (AOA) gives a useful description of what colour deficiencies are. To summarise:

• In common parlance, the condition may be termed 'colour blindness', although complete colour blindness (achromatopsia) is rare - such persons would see things only as black and white or in shades of gray (Ref: AOA, see link above).
• People with red-green colour deficiency have difficulty in differentiating between particular shades of reds and greens. It doesn't mean I can't see these colours at all - I have a harder time differentiating between reds and greens, depending on how dark or light the shade is.

 

I thought women don't usually get colour deficiencies! Are your parents colour blind?

• Yes, it is more common in men, because genetically, it follows an X-linked recessive pattern of inheritance. What does that mean?
  • For my colour deficiency to have been inherited, my father would have to have a colour deficiency, AND my mother would have to be a carrier of the gene. These Tables (charts) explain this. 
    • Colour deficiency symptoms do not show in carriers, so I wouldn't know if my mother carried the gene. However, the inheritance pattern ALSO requires the father to have colour deficient vision, so if my father has colour deficient vision, one could make some conjectures on the fact that my condition is inherited. 
    • My father does not have colour deficient vision.
    • In view of this (and the fact that my colour deficiency is highly unlikely to have been due to an external cause (see below), genetically, that makes me a mutant (and proud!) ;-) 
• Note: While the majority of colour deficiency cases are inherited, colour deficiencies or colour blindness can also be caused by external factors - e.g. certain medications, chemical exposure.

How does it affect your everyday life?

It isn't a major bother, although here are some pet peeves:

• Subway/transit maps. I would visually trace the red line to an interchange where you can opt to change to... oh no, there's a.. I think it's a... green, line? Or a brown line? So where does the red line go from the interchange? Is this other line red or green? Or brown? Help! It's all pretty much the same colour to me!
   
• Waze route directions that require me to differentiate between red and green. In particular, when one uses the 'Send ETA' function, the blue mapped route turns... green! (I think!) If you're in an area with heavy traffic (indicated by red lines), the screen will consist of green and red lines, which spells havoc, because to me, the green and red shades look very similar and they therefore blend together at first sight, and I suddenly wonder where my original mapped route (which was blue a little earlier) has 'disappeared' to. I stop the car, stop the route, and reset the route.
  • Note: I have posted a suggestion to Waze on this. Will update if any changes do result!
• Painting. Which is rather ironic, seeing that art is one of the things I do best! (I tell my friends - life is fair! :D)
  • True story: During an art class in secondary school, the teacher glanced at my work-in-progress of the scene of a family at a picnic, and asked, "Wen Li, why have you painted all the faces green?"
    Thereafter, I would paste handwritten labels on all my paint jars and lids, which would state the name of the colour of the paint it contained. Of particular difficulty for me was Light Green vs Yellow Ochre (which explains the earlier-mentioned green picnicking family).
     
  • A common question: So is this why my drawings tend to be in black and white? I'm not sure I have a conclusive answer to this. I would say no (at least not consciously); ink/line drawings happen to be my favourite genre, and I have always had an affinity for using a variety of intricate lines and drawn-out details to bring out textures, shades and emotions.  
• Graphic design/drawing applications. Again, ironic. In fact, this applies to any software application that involves the use of colour. 
  • When changing the colour of text in a document or slide, I make sure I hover my mouse above a desired colour to first double-check what colour it (really) is.
     
  • If I have to pick a colour from a palette or a swatch, it's pretty much hell on earth. Hex codes are my best friend. #000000 is black. #CCCCCC is white. #FFFF00 is standard (web) yellow. #FF0000 is standard (web) red. No hex codes? Let's convert Hex to RGB then. I have an RGB-Hex colour converter app on my phone, but what would be really useful would be an app that not only does conversion, but also names the colour (e.g. "light purple"/"medium red"/"dark brown"). If you know of such an app, please let me know!
• Red/green lights in car parks that are supposed to help you see, at a glance, whether there are any parking spots available ahead of you. They're of no use to me.
   
• Remember mobile phones in the 90s that required you to take out the entire battery pack to charge it, and the little light on the battery pack changes from red when the battery is flat, to green when it's fully charged? Let's just say I'm thankful that era is over.
   
• Back in school, chemistry lab sessions could be tricky, particularly when it involved:
  • Identifying whether it's Iron (II) (green) and Iron (III) (red) that's present in your compound.
  • When you're required to use Universal Indicator to check pH levels. Universal indicator produces smooth colour changes (which makes things worse!) depending on whether the solution you're testing is acidic (red), neutral (green) or alkaline (blue). I never saw red or green; it was just a generic dark colour to me. 
• Shopping alone. Forget the white-and-gold-or-blue-and-black-dress problem - I have more fundamental colour issues to resolve! If friends or family happen not to be checking their messages to respond to my frantic 'Need a colour consult!' text/photo messages, I will have to resort to asking the nearest salesperson, "Excuse me.. yes, I need some help.. what colour is this?" followed by "Yeah, I have really bad eyesight, yeah" in response to the saleperson's look of incredulity.
   
• Reading children's books about colour can turn out to be an embarrassing experience, but usually easily worked around using one of the following phrases: "Oh, yes of course you're right, it's green! What was I thinking? Ha ha!" / "What colour do YOU think it is?" / "I'll need to read this book in the daytime when the light is better. Let's pick another book..."
   
• I wouldn't exactly classify this as something from 'everyday life' but it sure made things difficult when it was a fad - an unsorted packet of multi-coloured 'Rainbow Loom' bands sets alarm bells off in my head. To yield the least frequency of mistakes when sorting out the colours - in particular the reds, greens, browns, blues, maybe-purples (I can't always tell if something is blue or 'could be purple' - I'm guessing it's the red shade in purple that I have difficulty with) - I'll need to lay out all the bands on a white surface, in bright sunlight, and then stare at each band in comparison to 'control' samples (which have been pre-identified and verified as being of certain colours by a person without colour deficient vision).

What would make things easier for you?

Why not patterns in shades of grey? 

• Patterns rather than colours. For people who do not have a colour deficiency, the use of colours as labels/legends makes perfect sense. This is not always the case for people whose colour vision is such that they can't differentiate between, e.g. red and green routes that intersect on a subway map.
• Using patterns on a subway map is probably not feasible. However this example of simple tweaks in one subway map - using curved lines where lines intersect and ensuring proper contrast in colours at intersections - does seems to work quite well. 
• The ultimate solution if technology were to make it possible? - Glasses that sense the colours within your field of vision and convey information about what certain colours are, perhaps at the touch of a button. :-D Until then, I'll just keep asking salespersons strange questions like "Excuse me, what colour are these shoes?"

So *can* you see the colours on traffic lights?

This always seems to be everyone's ultimate point of curiosity! :D

Yes, rest assured I can tell the difference between the red, amber and green on traffic lights - I won't see them in the same shades and intensity as you do, but I can tell the difference :) 

(Also, the fact that red is consistently on top and green at the bottom probably helps too!)