Horse has had slightly swollen eyelids for a while now - very variable so some days virtually no swelling, other days noticeable swelling with redness of the normally white tissues. These have been the only symptoms - no blinking, rubbing, abnormal discharge, obvious pain or behaviour changes. The vet looked at him today and thinks it is probably glaucoma - prescribed Danilon and an eye ointment. Another vet who hasn't seen the horse suggested that the swelling could be caused by an abscess behind the eye. This seems unlikely to me - I think that would be very painful and presumably would be secondary to some sort of injury which there hasn't been. I haven't spoken directly to either vet since this suggestion was made but will probably call in at the surgery tomorrow. Interested in experiences and opinions of either in the meantime!