Converse of object

• have: Within the field of vision, all people have a blind spot on the retina of the eye which cannot receive visual images.

• reduce: Is there a need for CCTV on the back of certain vehicles to eliminate or reduce blind spots during any unavoidable reversing?

Preposition: on

• retina: Within the field of vision, all people have a blind spot on the retina of the eye which cannot receive visual images.