visible light; visible radiation
Scientific term for the portion of the electromagnetic spectrum that is visible to the human eye.
Visible light is electromagnetic radiation with wavelengths from about 380 to 750 nanometers.
This camera can detect not only visible light but also infrared rays.
Infrared radiation, which has longer wavelengths than visible light and is felt as heat.
optical telescope
Compound of 可視 (kashi, 'visible') + 光 (kō, 'light'). The exact historical derivation is uncertain, but the term follows standard Sino-Japanese word formation patterns for scientific vocabulary.