• palming, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
• pencil fusion, 1
• perception, 1, 2, 3
• Perfect Sight Without Glasses  (W. H. Bates), 1, 2, 3
• peripheral vision, 1
• personality, 1, 2, 3, 4
• photogravure, 1
• photophobia, 1, 2, 3, 4
• photopigments, 1
• photoreceptors, 1, 2;
  • see also rods and cones
• picture fusion, 1
• playing-cards, 1, 2
• presbyopia, 1, 2, 3, 4, 5, 6, 7, 8, 9
• primary visual centre, 1, 2
• primitive man, 1, 2, 3
• pupil, 1, 2, 3
• Purkinje images, 1