RT Journal Article SR Electronic T1 MODIFIED DYNAMOMETER JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 378 OP 379 DO 10.1136/bjo.46.6.378 VO 46 IS 6 A1 Vernon H. Smith YR 1962 UL http://bjo.bmj.com/content/46/6/378.abstract AB