various kinds of blindness

I’ve been reading quite a bit about different kinds of blindness, recently. I’m thinking about what kind of relationship this has with invisibility, where maybe invisibility is not the state or quality of a thing, rather it describes a situation which occurs in the relationship between the observer and the world. Where, on the one hand, things can be invisible because they are beyond the scope of the eye, being too small, too far away or too fast to see, but on the other hand things are within the scope of the eye, but because of some kind of blindness we are unable to perceive them.

The other day I read a book by Oliver Sacks called The Island of the Colour-blind. It describes his research trips into Micronesia, and specifically to an island called Pingelap, where isolation, intermarriage and a congenital gene for achromatopsia had caused an unusually large number of the population to be totally colour-blind. This occurred after a typhoon killed more than 90% of the population of the tiny island in 1775. Of the twenty survivors it was the chief of the island who carried a recessive gene for achromatopsia, which spread rapidly through interbreeding. Achromatopes have no functioning cones in their eyes, so they are both unable to see colour as well as being so sensitive to light, that they can be blinded during the day. However, they have extremely good night vision and an increased receptiveness to form and texture, outlines and boundaries, perspective, depth and movement.

I wonder how the visual experience of an achromatope affects the way they perceive their world? It’s interesting to relate this to Elizabeth Grosz’s thoughts about the ‘island of the senses’, the world as a kind of bubble, which for each creature is a response to their individual sense organs. Grosz describes it (in reference to Estonian biologist, Jakob von Uexküll) as a kind of tune or melody that resonates with the individual “ego-tone” produced by the creature. For an achromatope, I imagine this bubble would be a remarkably different shape from than of the average person. Perhaps what they were lacking in their visual field would be compensated for by their other senses.

In the book, Sacks relates a story by H.G. Wells, in which a traveller stumbles upon a valley, and is perplexed by the oddly coloured houses there. He discovers that the inhabitants of the village have all been blind for generations, due to a disease contracted and passed on long ago. He views them as disabled at first, but in fact their other senses have become so much more sensitive, that they no longer need their eyes. Over the course of time the whole concept of seeing has vanished from their culture, even the language to do with sight has disappeared. Their imagination and relation to the world has adjusted according to the senses they use (sound, smell, touch, etc). Actually, it is the sighted traveller who is regarded as disabled by these people. I wonder how different these societies would be, compared to our ocular-centric culture?

But other than physical or neurological conditions which alter a person’s senses, I’ve also been reading (in issue 21 of Janus) about visual processes that affect us all, causing different kinds of blindness. A Japanese scientist, Ken Mogi has done a lot of research into something called ‘change blindness’. It’s phenomenon that affects everyone, causing you miss major changes in your visual field. For example objects which change place, appear or disappear during a saccade or some other visual interruption; it could be something as big as a change in conversation partner. Change blindness has to do with the processes of your visual short-term memory, in which what you see and what you are aware of is disconnected.

Similarly, cognitive blindness is a situation in which it is not the eye that fails to see; rather it is the mind that fails to comprehend something. Seeing occurs with the mind, the eyes are just the receivers. I think, sometimes failing to recognise something might have to do with the lack of vocabulary to describe it (and I’m sure it would be interesting to investigate how vision might be related to language). But perhaps, more often, it has to do with expectation. Because you expect something to be somewhere else, you don’t see it right in front of you. Maybe the most classic example is loosing your keys while they are right in front of you, because you expect them to be in another place.

There are many other phenomena in our visual processing which cause us to miss things or not register them. But what is clear, through all these everyday forms of inadvertent blindness, is how multilayered conscious experience really is.



A picture of an invisibilty cloak made by using a projection on retroreflector material, from Janus 21.