free debate

May 31, 2011

Reindeer See in Ultraviolet

Light is so much more than we can see. Human eyes have evolved over millions of years to be very sensitive to a very small sliver of all the different colors of light. Our eyes use those wavelengths of light that transmit well through our atmosphere and are most useful for finding food and predators. It is not surprising, though, that different animals that evolved in different environments than our own might have their eyes attuned to a slightly different set of colors than our own eyes. New research shows that reindeer may have just that ability.
"We discovered that reindeer can not only see ultraviolet light but they can also make sense of the image to find food and stay safe," said lead researcher Professor Glen Jeffery of the University College London (UCL). "Humans and almost all other mammals could never do this as our lenses just don't let UV through into the eye. In conditions where there is a lot of UV - when surrounded by snow, for example - it can be damaging to our eyes. In the process of blocking UV light from reaching the retina, our cornea and lens absorb its damaging energy and can be temporarily burned. The front of the eye becomes cloudy and so we call this snow blindness. Although this is normally reversible and plays a vital role to protect our sensitive retinas from potential damage, it is very painful."
Image Credit:Erik Christensen
Image shared via Creative Commons and Wikimedia Commons
So reindeer are not only seeing a part of the spectrum we are blind to, but one which is actually harmful to our eyes. It is also some wavelengths of ultraviolet light that will give you a sunburn. Still, these animals have adapted some mechanism for using this high energy light. Future research may lead to a better understanding of how their eyes are protected from this high energy light.

I have always wondered what it might be like to be able to see in some of those other parts of the spectrum. Reindeer are literally seeing the world in a way only accessible to us through the use of special ultraviolet cameras. This gives them an advantage in spotting predators and finding food in an environment that makes us nearly blind. Studying this could possibly give us in ways of protecting our own eyes form ultraviolet radiation or a myriad of other potential applications we can speculate on. It is impossible to know exactly what future technology this will bring about, if any. Still it is research like this, the research that surprises us and makes us think, that pushes science forward.