Eye chart smaller towards the bottom of the chart. The person removes any glasses or contact lenses, and stands or sits a standardized distance from the chart (e.g., 20 feet for the Snellen chart). The person is then asked to identify the optotypes on the chart, starting with large rows and continuing to smaller rows until the optotypes cannot be reliably identified any more. The row in which the person can reliably identify symbols defines the visual acuity. One eye is tested at a time. Practically, this is accomplished by covering the other eye with a hand, piece of paper, or a
The Name of the Rose fifty-six rooms. Each room has a scroll containing a verse from the Book of Revelation. The first letter of the verse is the letter corresponding to that room. The letters of adjacent rooms, read together, give the name of a region (e.g. Hibernia in the West tower), and those rooms contain books from that region. The geographical regions are: Two rooms have no lettering - the easternmost room, which has an altar, and the central room on the south tower, the so-called "finis Africae," which contains the most heavily guarded books, and can only be entered through a secret door.