Key points from article :
University of Pennsylvania used human cells to build a model of the surface of the eye.
Synthetic eye is equipped with a fake eyelid that mimics blinking.
Grew a ring of conjunctival cells around a circle of corneal cells on a contact lens.
Eyelid made of a thin hydrogel film spreads tear fluid over the cells.
Could help researchers study dry eye disease and test eye drop medications.
