RT Journal Article SR Electronic T1 The Eye (Comparative Physiology) Vol.5 JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 77 OP 77 DO 10.1136/bjo.60.1.77-b VO 60 IS 1 A1 R. Fisher YR 1976 UL http://bjo.bmj.com/content/60/1/77.3.abstract AB