RT Journal Article SR Electronic T1 Cranial Artefacts JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 74 OP 74 DO 10.1136/bjo.9.2.74 VO 9 IS 2 YR 1925 UL http://bjo.bmj.com/content/9/2/74.1.abstract AB