The Lenses

The Lenses are William of Baskerville's reading glasses, a pair of forked spectacles with glass ovals that he uses to read fine manuscripts. They are a crucial tool for his investigation, enabling him to decipher Venantius's secret notes, and their theft by Berengar of Arundel becomes a significant setback that forces William to rely on other methods until they are recovered.

Identity and Description

William of Baskerville carries a pair of reading glasses, which he calls his "oculi ad legendum" . The device consists of a forked pin that rests on his nose, with two ovals of metal holding thick glass almonds . He explains to Adso that these lenses compensate for the hardening of the eye that occurs after a man passes the middle point of his life, a condition that had left many learned men virtually unable to read or write after their fiftieth summer . William considers the invention a support for the ideas of his master Roger Bacon, who taught that the aim of learning was also to prolong human life .

Role in the Investigation

The lenses are essential to William's investigative work. When he and Adso find a page of Venantius's notes in the scriptorium, William puts on his lenses to read the tiny Greek characters (E01116–E01118). He uses the lenses again to examine the page, and it is while wearing them that he discovers the hidden zodiacal signs that appear when the parchment is heated (E01120–E01121). The lenses thus enable the first breakthrough in deciphering Venantius's secret message.

Theft and Recovery

During the same night in the scriptorium, while William and Adso are distracted by a noise, a mysterious figure snatches the lenses from the desk . William immediately realizes the gravity of the loss: without the lenses, he cannot read the fine Greek script on Venantius's page, and he knows that the thief, recognizing the value of the objects, has effectively blinded him for the purposes of the investigation . The theft forces William to seek new lenses from Nicholas of Morimondo, the master glazier, who attempts to grind a replacement pair . The original lenses are later found by Severinus of Sankt Wendel inside Berengar of Arundel's habit, confirming that Berengar was the thief who had been in the scriptorium that night .

Significance

The lenses are a concrete symbol of William's method: a reliance on precise observation and the tools of natural philosophy to extend human perception. Their theft and recovery mirror the larger pattern of concealment and revelation that drives the plot, and their role in deciphering Venantius's code marks a turning point in the investigation.