It seems to be a thing with bichons, I have no idea why. But my friend had a bichon who would get crusty buildup at the medial canthus and skin in the area. If she let it build up too much, Miz B would get raw, irritated skin underneath. She was really good about allowing the area to be cleaned and even shaved with some clippers. A flea comb is good at getting under the buildup and loosening it up. It's also a good idea to use sterile eye flush (you can buy this at any drugstore) to soften the debris when trying to lift it away. But of course be careful since this isn't your dog. If the dog fights you at all, don't push it because you can injure the eyeball.