This may be thin or serum-like, or it may be heavier, something like granulations.

The tissues are weak--they exude something in their distress, in their attempt to correct this condition when they have been inflamed.
"The pupil of your eye is the aperture, the stop of the lens.

That is the hole through which the light passes.

Around it lie the tissues of the iris.

In the back of the eye is the retina, which acts as a film for the eye's picture.
"Now, it was the part of the eye around that opening which got inflamed and began to exude.