Electromagnetic Spectrum and the Eye

The human eye is sensitive to only one part of the electromagnetic spectrum: visible light. Light is made up of electromagnetic particles that travel in waves. Every wavelength is represented by a different color. The human eye is able to “see” colors in the visible light portion of the spectrum. (An exception is an eye that has some type of color-blindness.) You might want to search for pictures of the electromagnetic spectrum on the Internet—some clearly show the position of the colors that are also often seen in a rainbow. Imagine cutting a horizontal slice from a rainbow and placing it in a straight line. From left to right the human eye can see violet, indigo, blue, green, yellow, orange, and red. The colors blur into each other without clear demarcations between each distinct color.