Towards the conclusion of the episode, we see
The long awaited Cleganebowl between Sandor and Gregor.
During this fight
Gregor gouges Sandor's eyes, similar to how he did with Oberyn Martell.
We see them visibly wounded, with blood pouring out, however they still appear to be able to finish the fight. Where would this blood have come from, whilst not robbing
Sandor
of his vision?
Eye gouging does not always lead to blindness, if you've ever played rugby or watched quite a bit of it you'd know it can be common among some players, especially in scrums and rucks and I'd reckon 99% of the time the player can carry on never mind going blind.
Although from watching the scene it is worth noting that after his eyes are gouged he doesn't actually need to see. He uses his hands to feel Gregor to find where to stab and when he's free simply runs forward at Gregor rather than anything that requires vision.
Gregor also seemed to be trying to crush Sandor's skull, like with Oberyn, so the full force of the crushing would be applied around the skull rather than solely into the eye sockets.
