|Yellow-crowned Night Heron (Nyctanassa violacea) composite with blown eye|
|American Oystercatcher (Haematopus palliatus) composite with blown eye|
I recently read about a congenital condition in humans called "iris colobomas" which is also found in other mammals and birds and have begun to wonder if that might not be the cause of the abnormal pupils I see in some species of birds instead of an injury to the eye.
|Great Horned Owl (Bubo virginianus) composite with blown eye|
I've seen this condition in the species I have shown in my images and I've also seen it occur in Bald Eagles.
None of the birds I have photographed with blown eyes appear to have any difficulty seeing and it doesn't seem to limit their ability to stalk or hunt prey. The Yellow-crowned Night Heron in the image above stalked, captured and ate three Ghost Crabs while I observed and photographed it. American Oystercatchers probe for their prey and none of the birds with blown eye that I observed exhibited any more difficulty in locating food than the adults nearby that did not have this condition. The Great Horned Owl with the blown eye was a male and the pair had three chicks and I am almost certain he had no difficulties providing food for them.
I wonder how many other species exhibit "blown eyes" and what the cause is. Injury or Congenital Defect. I would love to read additional input on this topic so please feel free to comment.