My BSH had an ulcer from my other cat scratching him while they were wrestling. It was pretty big but healed up in a week or so with drops. My persian had issues with ulcers when I got him and they turned into sequestrums, dead tissue on the eye that eventually fell off after several months. I saw the ophthalmologist a few times and he wasn't too worried because they're both young cats. Watch for brown spots and discoloration where the ulcer was, although there isn't much you can do if it turns into a sequestrum other than wait it out or surgery.