Humans cannot see ultraviolet (UV) light due to evolutionary adaptations of the eye, which developed sensitivity primarily to the visible light spectrum emitted by the sun. The cones in the human retina are specifically tuned to detect visible wavelengths, while UV light is absorbed rather than reflected by most materials. Additionally, UV radiation poses a risk of eye damage, leading to protective adaptations against its harmful effects. Insects like bees can perceive UV light, which is beneficial for their interaction with certain flowers that reflect UV wavelengths.
PREREQUISITESStudents studying biology, educators teaching about human vision, and anyone interested in the effects of UV light on health and the environment.
The sun is a strong source of ultraviolet radiation, but atmospheric absorption eliminates most of the shorter wavelengths. The eyes are quite susceptible to damage from ultraviolet radiation. Welders must wear protective eye shields because of the uv content of welding arcs can inflame the eyes. Snow-blindness is another example of uv inflamation; the snow reflects uv while most other substances absorb it strongly.