A light emitting diode (LED) based lamp may include a LED module having at least one LED to provide light, a housing to house the LED module, and a lens to receive the light from the LED and to direct the light in a specific direction. A microlens array may have a plurality of microlenses with a polygonal shape, and a distance between two opposing sides of one of the microlens is 0.7 mm to 1.2 mm.