Bird Retina Survives on Glucose, Not Oxygen

New research shows that the inner retina of birds can function without oxygen by relying on anaerobic glycolysis fueled by glucose supplied via the pecten oculi, while the outer retina uses oxygen. This arrangement supports the birds’ high-energy vision and reveals how the eye’s evolutionary tinkering may have evolved to maintain function during low-oxygen conditions, with potential implications for understanding tissue hypoxia in humans.