This morning a hawk attacked our chickens while they were playing in the front yard. I didn't see what happened but I heard them screaming and saw the hawk flying away. The other two seem fine but one of them refuses to open her left eye and she seems really tired. Her entire body keeps sinking to the floor and she's making a weird twitching motion every few seconds where her entire head moved really quickly just a few millimeters go the right. I can't tell if she's sleeping since her right eye is still open and I read somewhere that chickens can sleep with only one eye closed. We put a little eyedrop in her left eye and we when we moved her eyelids I didn't notice any problems. But then again it was only open for a second and I couldn't carefully inspect it. I'm worried she might have been infected or seriously injured. Hopefully she just needs rest.