Night vision in horses.

Research at the Equine Research Foundation shows that horses can distinguish simple geometrical shapes under low light conditions.

Horses were trained to choose between two shapes - a circle and a triangle. The next step was to see if they could still distinguish the shapes in conditions of increasing darkness. The lighting was controlled to give conditions ranging from the equivalent of twilight to a moonless night in a dense forest.

The study showed that the horses could see at very low light levels. They were able to choose between the two shapes in almost complete darkness. Only when it was as dark as a moonless night in dense forest were they unable to differentiatebetween the two shapes.

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