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.
It is, however, the only region that can be seen by the human eye. Visible radiation has wavelengths from approximately 400 to 750 nanometers (nm, 1 nm = 10 -9 m) and ranges in color from violet to red. White light, or sunlight, is composed of all of these colors. The table below shows the various colors of visible light and their corresponding wavelengths.