This slit-lamp photo was taken from an eye suffering from EKC (Epidemic Kerato conjunctivitis). The infiltrates seen are subepithelial, which you can see from this corneal cross-section as being on the surface.

This picture probably doesn’t make sense out of context … check out our epidemic keratoconjunctivitis video to see how these infiltrates light up as you sweep the light beam across the corneal surface.