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A hagioscope, also known as a squint or loricula, is an obliquely cut opening in the masonry wall of a Christian church to allow a limited view of the high altar from side-chapels or aisles. Its purpose was to allow celebrants in the side chapelsChristian place of prayer and worship, smaller than a church. to suspend their own services when the parish priest at the high altar reached the point of consecrating the eucharist, known as sacring, so that consecrations did not take place simultaneously.[1]
It has often been suggested that the squint allowed lepers to view the Mass without mixing with the congregation in the naveCentral part of a church, used by the laiety.,[2] and with that purpose in mind it is sometimes called a lychnoscope.[3] But during the medieval period the congregation would have been prevented from seeing the celebration of the Mass by a pulpitum, so the suggestion is almost certainly without merit.[4]