RT Journal Article SR Electronic T1 Clinical testing of visual fields using a laser pointer and a wall JF Practical Neurology JO Pract Neurol FD BMJ Publishing Group Ltd SP 258 OP 259 DO 10.1136/practneurol-2013-000562 VO 13 IS 4 A1 Richard Stark YR 2013 UL http://pn.bmj.com/content/13/4/258.abstract AB