The light-sensitive tissue of birds’ eyes is not supplied with oxygen by blood vessels – instead, it powers itself with a ...

A new study explains how birds maintain sharp eyesight despite their retinas lacking blood vessels, finally resolving a ...

Pulmonary function tests are a group of noninvasive breathing tests that measure how much air your lungs can hold, how ...

Neural tissue normally dies quickly without oxygen. Yet bird retinas—among the most energy-demanding tissues in the animal ...