The Bird Eye Was Pushed to an Evolutionary Extreme
2 days ago
- #avian physiology
- #evolutionary adaptation
- #anaerobic glycolysis
- Bird retinas lack blood vessels, unlike most vertebrates, despite being highly metabolically active.
- A 2026 study found bird retinas use anaerobic glycolysis for energy, not oxygen, with inner retinal layers in chronic anoxia.
- The pecten oculi structure in bird eyes pumps glucose into the retina to support anaerobic glycolysis and removes lactic acid.
- Bird vision is exceptional, possibly due to fewer obstructions from blood vessels and dense retinal cell packing.
- The anaerobic retinal system likely evolved in theropod dinosaurs for sharp vision and later aided high-altitude flight.
- Research on bird retinas may inspire treatments for oxygen deprivation conditions like strokes by understanding extreme adaptations.