The Human Eye
EM Waves -Light-Julia Kreiser and Jaeden Joyner
Visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light is usually defined as having a wavelength in the range of 400 nanometres to 700 nanometres. The frequency of light waves is about 300,000 kilometers per second. Nothing travels faster than light. Light was discovered by Isaac Newton in 1665 when he placed a triangular prism on his desk and saw the colors of a rainbow.
Light that enters the eye through the pupil ultimately strikes the inside surface of the eye known as the retina. The retina is lined with a variety of light sensing cells known as rods and cones. When light of a given wavelength enters the eye and strikes the cones of the retina, a chemical reaction is activated that results in an electrical impulse being sent along nerves to the brain.