Spectacles (Eyeglasses)

Convex lenses mounted in a frame to correct for presbyopia (farsightedness), dramatically extending the working life of scholars, scribes, and craftsmen.

Core metadata

ID: spectacles_eyeglasses
Era: Medieval
First known date: 1200 (century)
Region: Northern Italy
Review status: source_checked
Maturity: N/A

Prerequisites

Dependents

Fields

None.

Node sources

The history of spectacles (British Optical Association Museum / College of Optometrists, 2026, museum) • Supports: node
Locator: The museum history places the earliest spectacles in Northern Italy in the 13th century and describes rivet spectacles with convex lenses.

Prerequisite edge evidence

Edge/source evidence summary:

Prerequisite edges: 4
Average edge confidence: 70%
Prerequisite sources: 3
expert_inference: 4

Prerequisite	Type	Confidence	Evidence level	Note	Sources
Early Optics (early_optics)	historical_predecessor	75%	expert_inference	Early Optics is an earlier historical predecessor or foundation, not a one-to-one engineering dependency.	No sources recorded.
Glassmaking (glassmaking)	enabling	68%	expert_inference	Glassmaking provides a capability that enables this technology without being the only possible path.	Glass of the Ancient Mediterranean (McClung Museum of Natural History and Culture, 2013, museum) • Supports: edge
Bronze Working (bronze_working)	enabling	68%	expert_inference	Bronze Working provides a capability that enables this technology without being the only possible path.	Materials (NIST, 2026, generic_overview) • Supports: edge
Iron Working (iron_working)	enabling	68%	expert_inference	Iron Working provides a capability that enables this technology without being the only possible path.	5,000 years old Egyptian iron beads made from hammered meteoritic iron (Journal of Archaeological Science, 2013, primary_paper) • Supports: edge

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