Cursor sporadically changes from whatever tool i am using to cursor and back to tool

I am a Photo Retoucher, and I have run into an issue for the past couple of months in Photoshop where my cursor sporadically changes from whatever tool i am using to cursor and back to tool, and while it flickers it will appear in two seperate locations for both cursor and tool, so it is difficult to tell where my cursor is. When I do use my tool,  such as paint brush, the flickering stops and I can see what I am doing. Working on iMac and using a Magic Mouse.