It looks as if my 2 big Oscars have a bit of scratches over their eyes - sometimes it looks as if small oxygen bubbles clings on it, but then it goes away quickly. What could it be? Their eyes are very clear, no cloudiness or anything. They eat well and get a water change twice a week. Anyone knows what it is? There is a piece of wood in the tank, but it has been there since they are ther and I cannot imagine them hurting their eyes against it now?

Try and take a photograph if it happens again. I know it will probably be very difficult to get a clear one, it might just help get an idea what it is. How often does this happen? Do the eyes look good most of the time?

I will try my best for a good photo, but don't know if it will be possible - it's a like very, very fine crack on the eyeball - but both eyes on both fishes. Don't think it will be visible on a photo. It is only the last 3 days that I notice it, and I check the from "top to toe" twice a day. Apart of the "cracks/scratch", their eyes are just as bright and clear as always. They still follow me wherever I move when close to the tank and Ms Tiggy (the tiger) still attacks me viciously when cleaning their tank - in short, they don't act any different from usual. I'm really at a total loss on this one.

I think the first thing to do is make sure the water is in good condition. Also do some water tests, ammonia, nitrite and nitrate. In the past, I have found that when I introduced new fish into my tank, they got a very fine film on one of their eyes, this happened on both Oscars. It peeled off like sunburn after a while and there was never any problems after.

I think it is just best to keep a very close eye on it (if you pardon the pun) just to make sure it doesn't get any worse. If it doesn't clear up, or starts getting worse, you could try medication such as melafix or myxazin to see whether this helps or not. I think for the time being, increased the water changes will be a good idea. If you can keep the nitrates as low as possible, this is always good for fish healing

Sometimes after a water change (i fill with a hosepipe connected to a mixer tap) my oscars get little air bubbles on their bodys. This also has happened if they swim thro the air bubbles from the air pump. They dont last long as soon dissapear. Could it be this????