Random black thing in eye

Hey all.
Even since we have had Prince, I have noticed a random black thing in his eye. Its only in 1 eye and doesn't seem to bother him at all. I have been keeping a close eye on it and it has never changed size, but it does move. If he is standing up, its sat at the bottom of his eye and if he is on his back, it will move round to the top. I have tried to find out what it is, but nothing I have read seems close.
Here is Prince's eye. (Do you have any idea how hard it is to take a pic of a dogs eye?!)

Here is where the random black thing is. Behind the Cornea but in front of the Iris. In the Arterior Chamber.


Any ideas what it might be?

I can only think that it's a small hemorrage (is that how it's spelt?). To be honest, anything to do with eyes I get checked by the vet cause I'm really squeemish when it comes to eyes!