You may think that horses see the same as us; however they don’t see the world like we do. It will forever be a mystery as to exactly what horses see, although scientists have studied the components of their eye and have gained a further understanding of what they are capable of. Due to the structure and position of their eyes, horse’s eyesight differs greatly from ours in distance, colour, vividness and visual field.
The horse’s eyes are located on the sides of their heads, allowing them to have a much larger field of view than humans. With their head held at normal height, they possess an almost 360 degree field of vision around them – with only a small blind spot in the rear, the forehead and below their nose.
It is a common misconception that horses are colour blind, although this is not true, they don’t see colour as vividly as humans do. They only see two of the three visible wavelengths in the light spectrum, meaning that red or orange colours may appear as greenish or brownish in the eyes of a horse.
Horses are able to see much better at night then we do due to them having more of the structures that pick up light. These structures that improve their vision in dim light include; a larger pupil arranged as a rectangular slit; reflective tapetum (acting as an internal reflector); an increased amount of rod photoreceptors. Their complications with colours may be the reason that their vision is so good at night.
Although they don’t see all colours, their eyes are perfect for the lifestyle of a horse. The food they eat is essentially immobile as they don’t have to chase or capture any of their food, allowing most of their visual abilities to focus on their survival. As horses are very defensive in nature, their visual capabilities give them a greater advantage when detecting predators. They have an almost 360 degree view of their surroundings, a greater visual acuity, depth perception; and night vision – which all contribute to keeping them safe when in areas where they could be attacked.
A horse’s vision needs to be thoroughly understood when working with them. Knowing where they can and can’t see is imperative as they are startled easily and can act out if you sneak up on them without them knowing. It is also important to remember to trust your horse when out on the trails as they may be able to see a potential danger that you can’t – so if they get startled by something that may not be there, it is best to be very cautious.