'Cataract from Greek kataraktes, meaning waterfall or portcullis, an obstruction that descends from above.' Notes and reflections by one of our great soothsayers of seeing, John Berger, on the minor miracle of cataract surgery. With drawings by the Turkish artist Selcuk Demirel. 'If the doors of perception were cleansed every thing would appear to man as it is, infinite.' - William Blake