I’m absolutely not an expert but my first thought was planaria. Never had them in my tank but used to seeing them in the wild and caught them a few times. The shape is dead-on.
You make a good point about the noticeable eyes, although I’m not positive that’s always the case.
Edit: FWIW it’s hard to discern details from your photos. I can relate, trying to take pictures of limpets with my phone camera is rough.
Hard to say but the head does look quite triangular – which would mean planaria. Does it do an inch worm type movement or just move without any visible scrunching movements?
Thirding that this looks like a planarian to me as well. It has a spade-shaped head from what I can see.
I’ve read that they can predate tiny shrimplets but I’ve seen a few in my shrimp tanks before and they haven’t caused noticeable issues. If you’re worried, there are products made to kill them but in my experience most tanks have a few.
Limp-Set5606 
I’m absolutely not an expert but my first thought was planaria. Never had them in my tank but used to seeing them in the wild and caught them a few times. The shape is dead-on.
You make a good point about the noticeable eyes, although I’m not positive that’s always the case.
Edit: FWIW it’s hard to discern details from your photos. I can relate, trying to take pictures of limpets with my phone camera is rough.
Hard to say but the head does look quite triangular – which would mean planaria. Does it do an inch worm type movement or just move without any visible scrunching movements?
Thirding that this looks like a planarian to me as well. It has a spade-shaped head from what I can see.
I’ve read that they can predate tiny shrimplets but I’ve seen a few in my shrimp tanks before and they haven’t caused noticeable issues. If you’re worried, there are products made to kill them but in my experience most tanks have a few.
That’s planaria, its a deadly foe to your shrimps