George,
Irritated eyes are a frequent issue for our gun dogs, especially out in your country, but anywhere really. Dogs running through cover all day can pick up all manner of dust, dirt, pollen, weed seeds, grass awns, parts of weeds or crops, etc etc in their eyes.
I keep a couple of bottles of OTC saline solution and gauze pads in my vet kit. After every hunt, training session, etc the dogs get a tailgate exam to catch any issues early. Then I flush out their eyes with saline, wipe and repeat. You may be surprised just how much various gunk is flushed out!
Save the vet supplied eye ointment ( antibiotic, etc) for an actual eye inflammation ie conjunctivitis. Hope this helps.
NB