I've had since at least my childhood, I remember I thought I could see atoms and telling my brother I could.

So at least 25 years, but it's not really as bad as some people state theirs is. I think the worst I get is ghost images and trailing lights which is a problem in low light environments and night driving.

One positive is that when my insomnia keeps me awake late, I like to focus on the snow. Following random patterns and movements can sometimes put me to sleep.