Hagioscope

A hagioscope (from Ancient Greek άγιος (ágios) 'holy', and σκοπεῖν (skopeîn) 'to see') or squint is an architectural term denoting a small splayed opening or tunnel at seated eye-level, through an internal masonry dividing wall of a church in an oblique direction (south-east or north-east), giving worshippers a view of the altar and therefore of the elevation of the host. Where worshippers were separated from the high altar not by a solid wall of masonry but by a transparent parclose screen, a hagioscope was not required as a good view of the high altar was available to all within the sectioned-off area concerned. Where a squint was made in an external wall so that lepers and other non-desirables could see the service without coming into contact with the rest of the populace, they are termed leper windows or lychnoscopes.