A lens can effectively collimate or focus light from an LED, with options available for achieving a divergent or convergent angle smaller than 1 degree. For collimation, a focal length between 10-30mm is recommended, as a point source at the lens's focal distance will produce a parallel beam. The thin lens equation is essential for determining the appropriate lens specifications. Users should clarify whether they prefer collimation or focusing based on their specific application needs. Proper selection of the lens is crucial for optimal light output and direction.