So,,Ruby is my last surviving ex battery hen...she is approximately three years old...two days ago she did not leave the coop as usual, I took her off the roost and observed her behavior...she strutted across to her usual daytime area and walked straight into an obstacle which was so apparent to all of the others....I stood her at the edge of a small step..she had no inkling that it was there...she stumbled and I knew that she was blind...I passed my fingers across both of her eyes and no reaction whatsoever... Is it true that some Red feathered chickens go blind for no apparent reason ? She is the third of the ex-battery hens that has gone blind...I thought she may have ingested something toxic...but there is nothing in the area she frequents that could have attributed to this happening... Ruby is safe and secure...she eats and drinks well..she has freedom to roam within limits...yet another special needs girl...I am so l frustrated...any suggestions as to why this happens ? I hope she does not have Mareks...her pupils look normal and her general demeanour is normal....any pointers here from any of you who know details of Mareks and what other signs she may display if that is the potential reason? Any other suggestions are more than welcome for reasons or treatment for her to enhance her now limited life... Thanks for reading!