I have a two year old colt which I was hoping to take to the stallion passing at the show in Aug, but he has limited vision in one eye , does anyone know if this will be held against him or is there a chance he would pass if everything else was fine.

It may affect his vetting as the vets do check their eyes. Was it caused by an accident? If yes he may be OK but if it was something he was born with & likely to be hereditary then possibly not.
You are best to ring the society office & have a chat with the secretary - if necessary she will talk to the society vet about it.

Is there a passing this year? Do you know what stallions are going where?

No passing for the forest run stallions this year - the 5 year olds are staying out & the top 15 from last years passing are going where they were last year (unless they had been there for the 3 years in which case they'll be moved). And I think there are a couple of old stallions in the top 15 who wouldn't have gone back out anyway due to their age so their "place" will go to stallions further down the line.

2 & 3 year old "stud" colts are going for their inspections & there are over 20 booked in so far. Details are on the NF society website.

thanks HS for advice, vet seems to think it is recurrent uvietus, not sure it would be hereditery, this is the second pony to have this, my daughter bought a foal at the sales in Nov a big well grown filly paid top price, got her home and after a few days her eyes were running, so called the vet and was told there was so much scaring that she is virtually blind in both eyes and not much good for anything.