What is tyndall effect?+example

The Tyndall effect is the scattering of light as a light beam passes through a colloid. The individual suspension particles scatter and reflect light, making the beam visible. The amount of scattering depends on the frequency of the light and density of the particles. As with Rayleigh scattering, blue light is scattered more strongly than red light by the Tyndall effect. Another way to look at it is that longer wavelength light is transmitted, while shorter wavelength light is reflected by scattering. An example of the Tyndall Effect is how the headlights of a car are not able to shine all the way through fog. Headlights cannot penetrate fog because it is a colloidal substance, meaning that fog is made up of scattered particles. When light hits a substance with scattered particles, it collides with the particles, causing the light to scatter in multiple directions. Another example of the Tyndall Effect is the way certain eyes appear to be blue. This is because the turbid layer of blue eyes contains less melanin, a substance that absorbs light. With less melanin, wavelengths of light can pass through the turbid layer. The shortest lightwave reflects a blue color, so this is the color the eye appears to be.