This is probably going to seem immensely stupid, but this duck is my first and only, so I have no base for comparison. I'm fairly certain this is abnormal and would like to know if anyone has experience with it. Google has turned up nothing for me. My duck is a fawn and white runner, barely grown in to her feathers. One eye has a teardrop shaped pupil, most obvious when it is not dilated. Her other eye also has this teardrop shape also, except upside down. I could not get many photos and the one I have isn't too clear (will keep trying) so here is a drawing: Dilated, Not Dilated The upside-down tear drop. It looks a lot more dramatic than this when the pupil is pinned, but still you can see it is misshapen. When I first noticed the one after she finally got big enough for me to see such a thing, I figured oh! It must have been some kind of trauma! She did favor it for a day when she was about 2 weeks, after all. Then I saw the other, and it has the same kind of defect but upside down??? That is absolutely bizarre to me. It made me question if that was normal, if it was a rare duck disease, or if this poor girl hit the eye injury lottery. Her eyes are also doing their growing up color change, and they're not matching up. One is shades darker. It has been over a month since I first noticed this and I've not seen anything at all to worry me. If she has compromised vision, it is nothing that I can tell. So this isn't an emergency or anything of the sort. Just dang is it ever bothering me to not know!