Duck with closed eye

[Rory the Chicken]

I have a mini Appleyard who is living along with our other 3 ducks and 6 chickens. Today I started noticing one of her eyes was closing regularly and for quite a long time. I had a look and I saw something tiny inside it. I didn't want to interfere so I just refilled her water bucket in order for her to clean herself and hopefully dislodge the thing in her eye. Unfortunately it is still there. Is there anything I can do to help her eye and do you think she will be ok? She looks healthy and often snaps at flies, eats and drinks
An help would be much appreciated.

 

[casportpony]

Can you post some pictures?