Tyndall effect is usually observed in colloids. It is called the light scattering by the particles in a colloid. It is named after the physicist John Tyndall. The other name is Tyndall scattering or Tyndall effect.

is observed in our surroundings when
(i) Sunlight passes through a heterogeneous mixture such as the canopy of a dense forest.
(ii) a fine beam of light enters a dark room through a small hole.