RT Journal Article SR Electronic T1 Textbook of Ophthalmology JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 140 OP 141 DO 10.1136/bjo.63.2.140-d VO 63 IS 2 A1 Dobree, J. H. YR 1979 UL http://bjo.bmj.com/content/63/2/140.5.abstract AB