eye development trait optic cup morphology trait Any measurable or observable characteristic related to the shape, structure, color or pattern of the double walled structure formed by expansion and invagination of the distal end of the optic vesicle that develops into the pigmented and sensory layers of the retina; the mouth of the optic cup eventually forms the pupil of the eye. EFO:0006939 EFO:0006940 Trait.ontology VT:0004269