the good doctor on: Colour Vision

Blog #24

“Look at the different coloured leaves,

Swaying gently with the breeze,

Lovely reds, browns and greens,

All waiting to fall from the trees.”

This stanza from the poem, Autumn, by 10 year old Amy Boothby aptly captures the beauty of the season. What better time to wax lyrical about the fires of autumn. So wonderful to have the ability to see this leafy show.

Something we should never take for granted. Our colour vision is an amazing gift. Most of us have the full complement of colour receptors, cones in our retinas. They allow us to see the full range of colours from red to violet. There are some of us, mostly male and Caucasian, that lack one of the three receptors for colour. The eye usually has red, green and blue receptors that work together with the brains higher ordered neural pathways to provide colour vision. Due to a genetic mutation, some have only two typoes of receptors (dichromatism) which results in limited palette in colour vision. Taking it one step further, last week one of my patients presented with achromatism, having no colour receptors, seeing only in grey scale. Very interesting.

This is important for career counselling. It is vital that colour vision is tested at an early age so that the child can be steered away from vocations that require full colour perception, such as a police officer or airplane pilot. Also, being an interior designer would be very challenging for a dichromat. Whatever your colour receptors, everyone can still appreciate the fall colours, they just will be seen a little differently. Thankfully we have resources at hand, like Ontario Parks , that post the colour changes throughout provincial parks as the season progresses. But you do not have to travel far to see the fall show. We in the Golden Horseshoe are presently enjoying all its glory.

So get out and enjoy the colours, definitely something to be thankful for.


Til next week,


The Good Doctor, Dr. Mark Germain, Burlington Optometrist

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