Opacification of the posterior capsule of the lens frequently complicates extra capsular cataract surgery. The recent development of the pulsed YAG laser for the division of structures in the anterior segment of the eye has provided a novel means of restoring visual acuity following this complication. The complications of this procedure are described and discussed in the light of a preliminary study aimed at investigating changes taking place within the anterior chamber of the eye during the 24 hour period following application of laser treatment. No major problems were noted in 10 patients undergoing Q-switched Neodymium-YAG laser capsulotomy. The intra-ocular pressure was transiently raised following this procedure in 4 patients. In each case this decreased spontaneously. No changes in anterior chamber depth or gonioscopic appearances were observed. The current trends in the preferred technique for cataract surgery were assessed for the Western District of Glasgow. Extra-capsular surgery comprised 18.7 per cent of the total number of operations in 1980 and 1981; this increased to 55.5 per cent by 1984 to 1985 with a concomitant increase in the number of posterior capsulotomies performed. The implications of these results in terms of future health care planning are discussed.