Horses taken from a brightly lit area for loading into a trailer may lower their noses to the floor of the trailer, then raise their heads rather high for loading. In addition to smelling the trailer for identification, they may be trying to find the head position that gives them the best possible vision. They also may be biding time until their eyes adjust to the light change, a much slower adjustment than for humans. Horse handlers should allow plenty of time for loading young horses until they are well trained. A good system is to park a trailer in the horse lot and feed young horses in it.
Horses are color blind.
They do not perceive blue streams running through green fields, framed in trees with fall-colored leaves. They see a drab mosaic landscape with different amounts of light reflecting from it. Objects that remain still convey very little information to the brain. A sitting rabbit or bird may be seen readily by the rider, but may remain obscure to the horse until it moves. Horses see movement instantly and react according to temperament, experience and confidence in the rider.