A three-year-old impala – with eyes set on the side of his head. Sadly they rarely live much longer in the wild.
Meanwhile, back on the South African veld, where all this new technology is of little comfort to the grazing antelopes scanning the horizon and being eyed up by a hungry lion for his dinner.
Glenn Carp, of the London Vision Clinic, is also a keen photographer and took the pictures alongside these posts on a recent trip to Kenya. He explained to me how you can tell the age of an impala (a member of the antelope family). The horns on a one-year old are straight, a slight curve appears at the age of two; and at three they have an extra bend – unfortunately they rarely live to see their fourth birthdays.
Antelopes, along with other herbivores such as rabbits and buffaloes, have their eyes positioned on either side of their heads. In some such creatures of prey, the eyes move independently further increasing the field of view – for instance some birds can see for a full 360 degrees without moving their heads. This might be a handy tool for scanning the terrain for lush grass and possible danger; but not terrific for judging differences of distance.
Giraffes also have wide set eyes – ideal for spotting tasty greenery.
While researching the eye sight of the animal kingdom, I also discovered that some large predators – like sperm whales and killer whales – have their eyes positioned on opposite sides of their heads. Other exceptions to the rule include fruit bats and primates who have forward facing eyes (like us). In these cases the fine depth perception helps in being able to pick a chosen fruit or grasp a particular branch.
With good eyesight, we humans also enjoy and, probably take for granted our “stereoacuities” inherited perhaps from our caveman hunting ancestors. Something perhaps to consider the next time we forage through the supermarket fruit and veg counter or visit the butcher.
