I recently purchased 8 young chantecler chickens that are 8 weeks and 12 weeks old. One of the 4 cockerels is definitely half blind. It's one pupil is slightly grey and looks as if it's kind of hollow? Really don't know how to explain it.. but what I'm wondering is how young would signs of Mareks start to show? I'm thinking my best bet would be getting him tested (if I can find a place to test him) but just wondering if anyone else has had similar problems. Not the best pic but you can kind of see it..