Which region of the electromagnetic spectrum stimulates photoreceptor cells in the human retina?

Identify the range of wavelengths that photoreceptor cells respond to: Human photoreceptor cells are stimulated by visible light, which has wavelengths ranging from approximately 400 nm (violet) to 700 nm (red). This range is suitable for vision and does not include UV, IR, or microwave radiation.

Understand why other regions of the spectrum do not stimulate photoreceptor cells: Ultraviolet radiation has shorter wavelengths and higher energy, which can damage cells rather than stimulate them. Infrared radiation and microwaves have longer wavelengths and lower energy, which are not absorbed by photoreceptor cells for vision.