Friday, 25 January 2013

Vision and Colour (Science)


It always amazes me that for such a highly evolved animal (in terms of the way we think and the way our brain has developed) that humans have surprisingly limited vision. If you think about the spectrum of possible frequencies we could see it seems that the amount of light we are able to see (more commonly referred to as visible light) is somewhat limited.

It took my interest so I did a little research and found some quite interesting stuff on the internet about how other animals view things.

As is happens our eyesight comparably isn’t all that bad; as there are lots of animals which have worse eyesight- especially in terms of colour.
For example cats and dogs see things in a much duller way than we do; with less of an emphasis on colour and more emphasis on movement.

There was some information I was expecting to find; such as the fact that bees can see UV light. However I wasn't previously aware that snakes could possibly see Infra red light and some Birds and spiders could also see UV light.

Interesting things I found include the fact that
  • Horses have a large blind spot in there vision allowing them to look behind themselves
  • Snakes can adjust there eyes for the night and the day. Depending on whether it is day or night depends on whether its eyes are sensitive to a certain set of wavelengths.*
  • The mantis shrimp has evolved to have 12 types of photoreceptor; comparative to our 3. This gives it something called hyper-spectral colour; which I still don’t understand but it looks cool anyway.

Thanks for reading; I will post my sources. The first one is definitely worth looking at. J

*Though I looked up snakes further; some of the things different sites said opposed each other so it is hard to verify this point. However, I am fairly certain that snakes have “vision pits” which can detect heat. Personally I would be sceptical to start calling these “vision pits” a second pair of eyes though.






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