Practically each receptor is connected to a neuron. As a result, the eagle’s optic nerve, which carries messages from the eye to the brain, contains double the number of fibers found in that of a human.
यामुळे, डोळ्याकडून मेंदूला संदेश पाठवणारी गरुडाची दृक्‌तंत्रिका यात, मानवात आढळणाऱ्‍या तंतूंपेक्षा दुप्पट तंतू असतात.