Why does uniform illumination produce little response in many retinal and geniculate neurons?

Many retinal and geniculate neurons exhibit little response to uniform illumination because their receptive fields are organized in a concentric, centre-periphery arrangement characterized by lateral inhibition.12

In these neurons, the central region and the surrounding area typically have opposite responses—one is excitatory (on-response) while the other is inhibitory (off-response). When light illuminates the entire receptive field uniformly, the excitatory and inhibitory effects tend to cancel each other out.231

This mechanism is physiologically significant because it allows the visual system to emphasize non-uniformity, such as contours or moving objects, which are of greater interest to the animal than uniform fields. By suppressing responses to uniform light, the brain is spared from processing redundant information, effectively "keeping the retina quiet" and ensuring that neural resources are focused on detecting meaningful visual contrasts.12