What is the definition of visible light?

Visible light is defined as the portion of the electromagnetic spectrum that is detectable by the human eye. This includes wavelengths ranging approximately from 400 nanometers (violet) to about 700 nanometers (red). The reason this definition is significant is that it encompasses the range of light that allows us to perceive color and detail in our environment, which is essential for many aspects of daily life, including vision, photography, and various technologies such as lasers and displays.

The other options provide incorrect or irrelevant definitions. For instance, light that is invisible to the human eye pertains to wavelengths outside this spectrum, while light that cannot be measured does not relate to the concept of visibility. Furthermore, ultraviolet waves are outside the visible spectrum and do not contribute to what can be seen by humans. Thus, the option focusing on the light we are able to see clearly captures the accurate essence of visible light.