sometimes I see what looks like possible doubling when looking at a coin that is flat on the table. I usually rotate the coins to see it from all directions but as I rotate it the doubling disappears. I have always believed that what I saw was merely an illusion caused by either the light, angle or lousy vision. But I’ve always wondered if some doubling will appear when seen at some angles and not at others? Or will they always appear no matter how it is viewed?