Originally Posted by smrobs
Horses generally do see better than humans at night but it isn't always a good thing. I don't know if it is the shadows or what but most of the time if a horse is even slightly spooky on a regular day, they will be 10 times worse at night.
The thing to keep in mind at night with deep shadows or lights is that although horses do see much better than we do in low light, their eyes take longer to adjust to changes in light than ours. This is a reason that many horses will pause for a minute when going from even moonlight into a deep shadow.