Computer simulation of gravitational lensing. This is a process whereby light passing a nearby massive object is deflected slightly toward the mass. Instead of travelling in a straight line light is bent by the curvature of space and time in line with Einstein's predictions in his General Theory of Relativity. Visually the effect is somewhat similar to that of a magnifying glass where light is refracted by the glass medium. There’s a special situation known as an Einstein Ring, where a more distant galaxy is warped by a nearby galaxy into a complete circle. To date a few partial rings have been seen, but no perfect Einstein Ring has ever been spotted.