Cod liver oil - a potentially toxic source of Vitamin A: Hypervitaminosis A can result from ingestion of too much vitamin A from diet, supplements, or prescription medications.
This visible light region consists of a spectrum of wavelengths that range from approximately 700 nanometers (abbreviated nm) to approximately 400 nm. Expressed in more familiar units, the range of wavelengths extends from 7 x 10 -7 meter to 4 x 10 -7 meter.
Visible light energy is just one form of light energy. There are invisible forms of light energy, or light energy we cannot see, such as infrared, ultraviolet, radio and x-ray light energy. All light energy is generated by light waves.