From the picture is it popeye? If so i believe it should sort itself in time

Both eyes + swollen means probably infection rather than injury.
It might resolve itself,  if it's not getting better then put him in a quarantine tank and treat with Myaxin or similar.

Agree , possibly dropsy ...

Would you believe it!
I've fallen at the first hurdle. One of the two clowns I bought yesterday has a popped eye, it's a little cloudy that eye too.
To be honest, I couldn't say if it was like that when I got it cos the lights weren't on, and in the good daylight I can see it today.
Trying to catch it is not an option, there's so many nooks and crannies it'll get away easily.
There's nothing else in the DT but these two (they were bought a decent size, which gave me hope they'd be good, from the LFS but previously from another tank) and obviously the fishes know each other.
Given that there's nothing else in the DT and I don't have a QT, what should I do people?

Thanks @mightyhatter. I couldn't argue that the two of them are super active, but neither are they hiding away.
They hang about together a lot (not too closely) and in the morning they were in the corner but have gradually come out to the center and swim about.
They have done a bit of eating garlic brineshrimp, but not loads.
As the lights aren't on, and there's a broad expanse of light coming from outside the DT, and I have white walls, it's hardly surprising they're not too keen on venturing out a great deal, so I'm not vastly worried at the moment, but it's hardly the most auspicious start is it?
Is there something I should add in the way of medecine? Or just leave them for now?
Preliminary tests have indicated 0 ammonia and 0 nitrite

Thanks for all messages of support.
In reality, I maybe overreacted as I've now tested water further and found water quality to be quite good (15ppm nitrate 0.29 phosphate) not perfect but certainly good enough for fish.
I'm now convinced he scratched his eye somewhere, and whatever happens, happens. I've done what I could.
What is interesting though, is when I put in the garlicy brine shrimp frozen food, they'll sometimes swallow and spit it out, is it possible some fish don't like garlic? What do clowns tend to like?

As it's a single eye, it could just be a little injury from when they caught it in the shop. In that case it stands a good chance of healing with no intervention. 👍