What form can contact the eye's gross faculty?

Form is divided into the form of the essential realm (fundamental object), the form of the object-with-essence realm, and the form of the nature realm. Among these, the outer material sense-object (outer rūpa-viṣaya) of the essential realm can only be contacted by the eighth consciousness; neither the eye consciousness, the mind consciousness, nor the gross eye faculty can contact it, and the manas cannot contact it either. After the eighth consciousness contacts the essential realm, it further manifests the object-with-essence realm based on the four great element particles of the essential realm; this portion of form can be contacted by the manas and can also be transmitted to the gross eye faculty. What the gross eye faculty contacts is the four great element particles of the object-with-essence realm manifested once again by the eighth consciousness, not the four great element particles of the essential realm itself. Therefore, the gross eye faculty cannot contact the form of the essential realm; only when there is a certain distance from the essential realm can the form be transmitted into the supreme faculty (indriya). When faculty and object come into contact, the eye consciousness then arises to see form.

If the gross eye faculty were to directly contact the form of the essential realm, with no certain distance in between, the tathāgatagarbha would be unable to transmit the object-with-essence realm, manifested from the essential realm, through the gross faculty into the supreme faculty, and the eye consciousness could not arise to see form. Because the transmission of form by the eye faculty is rather special, there is an imaging principle of the eye faculty: only when there is a distance between the form and the eye faculty can an inverted image be formed on the retina of the eye faculty. The other faculties do not have this phenomenon; they do not need to maintain a certain distance from their corresponding material forms. Therefore, seeing form with the eye has one additional condition compared to the other faculties perceiving their objects: the condition of spatial distance.