Eyes are the windows to the soul.
I have loads and loads of horse eye pictures. They are so expressive and difficult to catch a horse eye without your reflection or the reflection of the surroundings in it.
A patch of thinner hair around the eyes of a horse in the summer (most commonly seen on greys as the black skin shows up better) is called an "eye patch" The dark skin will show around the eye as the smaller hairs shed out if the horse is in good health. Unfortunately I do not have a recent picture of eye patches I will leave that for another time.
Click the link at the top of this post to see more of my equine eye photo's.