The ability to see different forms of electromagnetic radiation, including visible light, infrared, and ultraviolet rays, is determined by the range of wavelengths that our eyes are sensitive to. Our eyes contain specialized cells called photoreceptors, specifically cone cells and rod cells, which are responsible for detecting and converting light into electrical signals that are then processed by the brain.
Visible light is the specific range of electromagnetic radiation that falls within the wavelength range of approximately 400 to 700 nanometers (nm). This range of wavelengths corresponds to the colors of light that we can perceive, including red, orange, yellow, green, blue, indigo, and violet.
Infrared radiation has longer wavelengths than visible light, typically ranging from around 700 nm to 1 millimeter (mm). Although our eyes cannot directly detect infrared radiation, some animals, such as certain snakes and insects, have specialized infrared receptors that enable them to perceive thermal radiation.
Ultraviolet (UV) radiation has shorter wavelengths than visible light, typically ranging from around 10 nm to 400 nm. While our eyes are not sensitive to UV radiation, prolonged exposure to certain wavelengths of UV radiation can cause damage to the eyes and skin.
The ability to see different forms of electromagnetic radiation is determined by the sensitivity of our photoreceptors and the corresponding range of wavelengths they can detect. The visible light range happens to align with the range of wavelengths that our eyes are most sensitive to, allowing us to perceive these wavelengths as different colors. However, other organisms, such as insects or birds, may have different ranges of sensitivity and can perceive additional portions of the electromagnetic spectrum.
It's important to note that although we cannot see infrared or UV radiation, we have developed technologies such as infrared cameras or UV lights that can detect and visualize these types of electromagnetic radiation.