animate radial-gradient CSS3 : move from left to right?

Question

I want animate a background with a radial-gradient radial-gradient(circle, rgba(255,255,255,0.8) 0, rgba(255,255,255,0) 100%), to move it from left to right

http://jsfiddle.net/odsb1fjh/2/

how can I do to animate this radial-gradient to move infinite on div from left to right?

I have already try animation and keyframe background-position: left/right bottom; but don't works.

Answer 1

"but we can see the border of "square" where is the light radial" - Why use radial background at all, simply use:

div

div {
  position: absolute;
  width: 250px;
  height: 250px;
  background-color: black;
  background-image: url(http://frontend.lostboys.nl/presenations/Icons-fonts/img/chrome.png);
  overflow: hidden;
}
div:after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgb(255, 255, 255);
  background: linear-gradient(
    90deg,
    rgba(250, 250, 250, 0) 0%,
    rgba(250, 250, 250, 0.5) 60%,
    rgba(250, 250, 250, 0) 100%
  );
  -webkit-animation: animation 3s ease-in-out infinite;
}
@-webkit-keyframes animation {
  from {
    left: -250px;
  }
  to {
    left: 250px;
  }
}

<div></div>