Tag Archives: Eyes

September 9, 2022: Flyway Morning and True Night

September 9, 2022: Morning on the Flyway

It’s September 9 and migration is well underway for many birds! According to birdcast.info (https://birdcast.info/) the next couple of nights should be very busy for nocturnal migrants along the length of the Mississippi Flyway. Good luck, everybody. We hope to see you next year! We were asked about some terms I used in our last eagle postcard. So what is true night? Let’s start with twilight! The Oxford Dictionary defines twilight as ‘The soft glowing light from the sky when

Dr. Laura on Mom’s Eye

January 29, 2020: Mom's eye up close

Thanks to our camera operators’ diligent work and John’s high-powered cameras, we got some excellent photos of Mom’s right eye today! We forwarded them to Dr. Laura, who said: I think that what we are seeing is a scar on the cornea; the cornea becomes opaque instead of clear when it’s been damaged. It does appear slightly raised, which is a bit unusual, so she could also have a foreign object (a small piece of bark, a stick, a grass

Eagle Eyes!

Human Eye versus Eagle Eye

Has anyone ever called you eagle-eyed? Relative to humans, bald eagles have larger, sharper eyes that see further, collect more details, and produce stereoscopic vision to greatly improve depth perception. A bald eagle’s visual acuity begins with its eye size and shape. Dad’s somewhat tubular eyes occupy over 50% of the volume of his skull, as compared with less than 5% in us spherically-eyed human types.  He can voluntarily adjust the curvature of his large cornea and lens (we’re restricted