Kuritza, no, you can't limit a horses view in the direction it is supposed to walk, or it will not walk at all. And you woulnd't want it to, as it would stumble and fall over within very few meters. And that's something that you definitly do not want if you're atop on it in heavy armor ... .
Neither do you want to crash head on into a wall of pikes, as you (and horse) would be very very dead in short time.
The cavalry wouldn't stop all of a sudden. The horses would start to balk as soon as they see where the ride is going, they would slow down and turn away to the side.
Yes, if the front would stop those behind would be in trouble. Yes, all of them (infantry included) where in big trouble when they literally run into each other all of s sudden without any room for the horses to evade.
I wrote about all this
here already ...