The visibility, blur radius, opacity, and auto-shading radius settings can all be animated, if you choose. This can be useful if you want to make something appear to fade in or out via the Opacity setting, or perhaps, you want to create the effect of a layer coming into focus—that is going from blurry to sharp—with the blurred radius. You can also choose to make something invisible, and then have it reappear anytime you want using the visibility setting. All it requires is checking a box and placing your keyframes on the timeline. The following steps will help you understand how to animate layer effects:
At the top of the Layer Settings panel is an option named Allow animated layer effects. Make sure it's checked.
Advance to frame 24 on your timeline.
Adjust the Blur radius to
Click on Apply. Notice how there is now a Blur radius channel on your Channels timeline along with two keyframes. This is shown in the following screenshot: