When I turn my head to look at a clock on the wall, sometimes the second hand seems to hang for more than a second before moving onto the next second position.
I’ve seen it mentioned on TV before with regards the means the brain uses to help interpret what we see, but I can’t remember what causes it.
Persistence of vision. But this should not come into play with such a slow-moving object as a second hand on a clock. Things have to be moving at least sixteen times faster before our visual sense “sees” it as a lagging or persistent image.
I suspect your clock might be broken 
this has come up before…but I don’t feel like finding the thread.
It has to do with the expectation of the brain. You look at a clock so many times in your life that your brain figures out that the average wait time is half a second until the next tick, and gets used to that interval. When it’s shorter than the 1/2-second average, you don’t think much of it because you realize that you just caught it in time. Then your mind has the right bearings to anticipate the next one.
But when you see the clock with almost a full second until the next tick, it conflicts with your internal expectations and sense of timing. The nearly full second seems so much longer because it drags on forever compared to your half-second subconscious timer.
I suppose you are talking about clocks with a second had that steps rather than sweeps from second to second.
My guess, and that’s all it is, is that we aren’t good judges of just how long a second is and catch it just after it has jumped to a new second. A second can seem fairly long when you are just sitting, or standing, there waiting for a second hand to jump.
Get a hobby so you won’t have so much time on your hands.
Well, the jobs not doing enough obviously. Either a hobby or lower my brain’s expectations 
Thanks for the answers 
Not to be confused with The Persistence of Memory.
Does Persistence of Vision apply to the following?
Sometimes when I’m riding along as a passenger, I see a sign that’s too heavy with text to read as we speed past it.
But then, I can play it back in memory and “read” it.
That sounds more like eidetic memory
I wish!
I took a pretty comprehensive IQ test back in 1990, and part of it required that I listen to a string of numbers and then recite them back. (I think there might have been a section where I had to give the number backwards.) Well the gal started with a short string and they gradually got longer. I kept spitting out the answers so consistentky she got a little uneasy, and went to the next section of the test.
But similar to the sign thing, I’d listen and then recite it as I replayed the sounds (of her saying the numbers) in my head. Oh. I also listened to the numbers in groups - threes and fours - and that helped immeasurably.
But as much as I’d like to, I don’t have anything resembling a prodigious memory.
Well you do have visual and aural “registers” that can replay stuff in your mind for several seconds. Perhaps yours are bigger. I notice the phenomenon myself when reading signs or quickly-switching video clips.
Then again, once in awhile I have a near-perfect aural memory in that I can replay stuff in my brain to the point that years after hearing something, I can finally decipher the words where before I only remembered sounds! But this mainly works for songs for me.
I saw a replay of something on television a few nights ago that I would not have had the opportunity to see since it’s original broadcast in 1955. It was of a certain opera star standing and singing in a classroom in a plaid dress with a white collar. She had spectacles. The song was “I’ll Follow My Secret Heart.” I’ve had no lingering memory of that presentation. Yet, when I saw it, I remembered seeing it before when I was eleven or twelve. And I remembered the song – both the lyrics and the music. (It’s possible that I may have heard the song since that time.)
That little snippet of television has been hiding out in my brain for fifty years. The program was from a series called Firestone Presents.