thumb|231x231px|A light source passes behind a gravitational lens (invisible point mass placed in the center of the image). The aqua circle is the light source as it would be seen if there were no lens, while white spots are the multiple images of the source (see Einstein ring).
thumb|231x231px|A light source passes behi.nd a gravitational lens (invisible point mass placed in the center of the image) The aqua circle is the light source as it would be seen if there were no lens while white spots are the multiple images o,f the source (see Einstein ring).