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A close-up view of barred owls’ eyes

Nov. 18, 2015

a winking barred owl sitting in a tree

(Photo by: Alannyiri. Source: Wikimedia Commons)

The wide-eyed owl, blinking quietly in an oak tree, is often used to symbolize wisdom. Paradoxically, little is actually known about the structure of owl eyes, particularly their eyelids, due primarily to restrictions placed on collection of tissues from these protected animals.

Now, in a new report published in PLOS One, Dr. Tom Phillips and Brian Jochems, BS ’13, provide the first histological characterization of the barred owl’s eye.

The scientists received the eyes from six barred owls that were euthanized after suffering terminal injuries that prevented their humane treatment or recovery. Following dissection and treatment with fluorescent dyes, the gross and fine cellular structures of the birds’ eyes were visualized using advanced imaging techniques. The researchers paid particular attention to the third eyelid, the so-called nictitating membrane that sweeps horizontally across the bird’s eye to keep it clean and healthy. According to the report, “[the] present study is the first histological and fine structure characterization of the upper and lower eyelids, as well as the third eyelid, of the barred owl.”

Jochems and Phillips say their study may prompt future comparative studies in other birds and enhance knowledge about the adaptive significance and evolutionary history of the third eyelid in birds.

Read the study: Jochems, B., Phillips, TE. Histological and ultrastructural studies on the conjunctiva of the barred owl (Strix varia). PLOS One. DOI: 10.1371/journal.pone.0142783


Related research strengths:
Cell Biology, Molecular Biology