Why can a blow to the eye make a person see stars according to the law of specific nerve energies?

According to the law of specific nerve energies, formulated by Johannes Müller, each sensory organ is inherently wired to report its own specific type of sensation, regardless of the nature of the stimulus applied to it.12

When a person receives a blow to the eye, the physical pressure acts as a mechanical stimulus on the retina or the visual nerves. Because the visual system is specialized to interpret any input as light, the brain perceives this mechanical disturbance as a visual experience—often described as "seeing stars" or phosphenes.341

Hermann von Helmholtz utilized this principle to explore the philosophical implications of perception, noting that because the eye reports its own "energy" rather than the true nature of an external object, our senses do not always provide an accurate reflection of the external world. This realization was central to his work in physiological optics, as he sought to understand how the mind constructs a coherent perception of reality from these potentially ambiguous sensory signals.1