RT Journal Article SR Electronic T1 The Retina: An Approachable Part of the Brain JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 479 OP 480 DO 10.1136/bjo.73.6.479 VO 73 IS 6 A1 John Marshall YR 1989 UL http://bjo.bmj.com/content/73/6/479.abstract AB