Defining Aberration:
The obvious change in the position of a light-emitting object due to the fidelity of the speed of light and the motion of the observer in relation to the emitter. The effect is non-relativistic; that is, special relativity is not requisite to derive it: all that required is Newtonian mechanics and the supposition of the constancy of the speed of light. The consequence is observable in the obvious change of position of stars due to the Earth's relative motion, and is accountable for the "tunnel vision" result of travelling at relativistic speeds.