I used them for a seriously neurotic horse and they did help a bit. I wouldn't buy the 'horse' ones though - just get some sheets of mirrored polystyrene (about £12 for 1m x 2m)
I also used to hang toys up on the walls of the stable for my horse. He was probably as bad as they can be in terms of stressing and weaving, though, so I would expect greater improvement from a semi-normal horse!
My horse has a mirror and he loves it - spends all day stareing at himself
He used to hate it when other horses walked past his stable, or when the horse next to him left the stable. He'd literally throw himself at the door and start bucking in his stable and get himself really sweated up. Now hes the calmest horse in the world in the stable - its totally changed him.
But i might add he LOVES other horses, so his 'friend' is an added bonus for him
It was a miracle for our young horse on box rest and he still adores it months later, but our other horse hated it in his stable but loved it in the other horses stable. If you buy one make sure it is placed high so it is difficult to kick and put on a flat wall or buy with backing board, also make sure it is predrilled
Have just had one delivered off ebay and very rapidly too! Pre drilled with curved corners and complete with fittings it was about £35 with postage for an acrylic mirror 4' by 2'6". I just hope he likes it at his new yard
Grace used to become neurotic when my other mare left the yard (there were 15 others to keep her company but none were Hannah!). I was at my wits end because she started rearing up at the walls and just wouldn't settle.
I bought a mirror and it was an instant transformation... she became relaxed in her stable, stopped stressing all the weight off and is now more than happy to be on her own in the yard with her 'friend'. She nuzzles up next to it if there is a scary noise (like a drill) and kisses it to death. She is now extremely chilled out in the stable and a completely different horse to be around in the yard.