Can I ask you to provide enough code for me to reproduce the bug?
//Create a geoFenceCircle fence = new geoFenceCircle(triggerPoint.latitude, triggerPoint.longitude, 0.009, watchOptions); //Use the distance from the geoFenceCircle to map the blur. blurFactor = map(fence.distance,0,0.12,0,40,true); //Select the image and adjust the blur filter. var gameImage = document.querySelector(".game-image"); gameImage.style.filter = "blur(" + blurFactor + "px)";
You can decouple your location events from the blurring so to isolate the glitch effect and to reproduce it more easily. You could use the mouse event and the map function to simulate the factors that drive the blurring effect. Notice is important to provide full code for this type of issues as well as browser version and OS.
Did you try any other browsers by any chance? Do you see the problem there as well?