If there were no electric charges, we would not be able to see light or detect other forms of electromagnetic radiation. The existence and detection of electromagnetic radiation are intimately tied to the interaction between electric charges and electromagnetic fields.
Electromagnetic radiation, including light, is produced by the acceleration or oscillation of electric charges. When an electric charge accelerates or undergoes changes in its motion, it creates changing electric and magnetic fields that propagate as electromagnetic waves. These waves carry energy and information through space.
The human visual system, for example, relies on the interaction of light with the specialized cells in our eyes called photoreceptors. These photoreceptors contain molecules that can absorb photons of specific wavelengths, converting them into electrical signals that are then processed by our brains to form visual perceptions.
Similarly, the detection of other forms of electromagnetic radiation, such as radio waves, microwaves, X-rays, or gamma rays, relies on interactions between the electromagnetic waves and electric charges in specialized devices or materials. For instance, radio antennas detect radio waves by inducing electric currents in response to the varying electric fields of the waves.
Without the presence of electric charges, there would be no source of electromagnetic radiation, and therefore no way to generate or detect it. Electromagnetic radiation requires charged particles and their interactions to exist and be observed.