Image Effects keep on rendering

Hello, I am using Unity 5 and the image effects provided by Unity. When I apply an effect such as Twirl or Vortex to Camera, it keeps on rendering and in the case of these 2 image effects, it keeps on rotating image from the center. This happens when I am testing on iOS device. If I test it in Unity Editor, it works fine. How can I stop this issue? So that rendering is done once. Thank you.