Better Vision – New Year Thoughts and Octopus Eyes

By The Marine Detective on December 31, 2019

[Update in 2021: CLEARLY I had no idea what a globally and colossally crap year 2020 was going to be when I wrote this blog. May the thoughts and information about octopus eyes still provide vision 🙂 ].
 
Here’s an unlikely combination of introspection and natural history. It’s what results when you bring together a photo of a Giant Pacific Octopus’ eye with the bad word play of “2020 vision” regarding the new year.

Introspection: In a human lifetime, you don’t get to cross the threshold into all too many decades. Like many of you, it makes me take pause . . . wanting to understand where we are and how to move forward with focus. It’s what happens when you want to make sense of a world which appears to have increasing numbers of cartoon-character-like heads of state. It makes me think about the state of heads, and how to find one’s way without despondency, denial and inaction.

I write these words largely to solidify my resolve and vision in this decadal transition but share them here in the hopes that they may be of use to you.

Better vision for better futures:

1. The paradigm: Realizing why there are forces in the world who would rather flirt with the health of future generations than undertake action that would benefit their own grandchildren. They are those who have benefited the most from lack of equality, fossil-fuel use, rampant consumerism, and use of disposables. Despite the enormity of their power, positive change is happening and in the death throes of the paradigm, the very nature of truth is being challenged. When one shouts loudly, it is not likely they are more correct. It is an attempt to drown out the truth. They are the spasmodic utterances of the entitled. The aims are confusion, distraction, discontent (just keep buying more little girl and happiness will be yours), despondency, overwhelm and (of course) the blunt tool of FEAR. The hope is that we shut down and not notice the steps forward toward a paradigm based on greater equality and sustainability.
2. Less is more: These are words I have shared so often. Above a true level of need, using less is not about loss. It’s about gain. The more we steer away from the myth that owning more and/or bigger is best or that it equates to “success”, the more liberation we have from being enslaved to $. We do know where true happiness lies. It is where there is greater sense connection, health and time for who and what we love.  What a world it would be if more of us saw that gain and realized just how empowered we are to create change through our consumer and voter action. Using less fossil fuels, dangerous chemicals and disposables positively impacts so many socio-environmental issues.
3. The way forward: You’ve seen it haven’t you? The uprising, the unblinking truth . . . the power of youth who know the way. How excited I am for power shifting further toward them, their technologies and lifestyles fuelled by values of equality and sustainability. In no way does that mean we stand idle and wait for them to be of the age to vote. For me it is to be in service of them, the next generation. It is to help others see the way, to know their place in nature, to know their power, to find their voice, and to shield them from despondency, and fear.  

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And here’s the natural history and marine mystery bit relating to the photo of the octopus’ eye (note that she was in her den and that I used a zoom lens).

Octopus vision:

You see that the pupil’s shape is very different from ours. Their retina is very different too.

Octopuses and other cephalopods have only one kind of photoreceptor cell while we have rod cells and three types of cone cells allowing us to see in colour. So how can cephalopods discern colour when they have only one kind of light receptor in their eyes? And they must be able to discern differences in colour. Consider how they signal with colour and how they camouflage.

Research from 2016* puts forward that their uniquely shaped pupils act like prisms, scattering light into different wavelengths (chromatic aberration), rather than focussing the light into a beam onto the retina.  The hypothesis, tested with computer modelling, is that cephalopods can then focus the different wavelengths onto their retina separately by changing the distance between the lens and the retina, thereby separating the stimuli and discerning colour. Note that the sharpness of their vision is believed to be different for different wavelengths / colours.

Even with their eyes closed, octopuses can detect light with their skin. This is tied to their ability to camouflage with the photoreceptors in their skin responding to specific wavelengths of light (different wavelengths = different colours).

Note too that octopuses do not have eyelids. They have have a ring-shaped muscular fold of skin around the eye that closes in the way of an eyelid (especially when some annoying human is taking photos).

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There, I feel much better now. Bring on the New Year.

Here’s to all the colour, marvellous mysteries, clear vision, and solid action ahead.

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*Sources

Katz, I., Shomrat, T., & Nesher, N. (January 01, 2021). Feel the light: sight-independent negative phototactic response in octopus arms. The Journal of Experimental Biology, 224.

Stubbs, A. L., & Stubbs, C. W. (July 19, 2016). Spectral discrimination in color blind animals via chromatic aberration and pupil shape. Proceedings of the National Academy of Sciences of the United States of America, 113, 29, 8206-8211.