20:20 vision shapes the way we view our world. It dictates modern categories of ocular functioning as well as the degree to which technology should ameliorate it. This book traces the Victorian origins of 20:20 vision. As the first full-length historical study of spectacles and vision testing, it draws together existing scholarship on ophthalmology, medicalisation, disability, normalisation, assistive technology, fashion, medical capitalism and sensory history. It interconnects these often disparate fields of study, and offers new insights into how technology - and its related historical actors - shape the meaning and experience of sensory perception and disability more broadly. In considering the ways in which spectacles altered the experience and meaning of seeing in a variety of different contexts, Spectacles and the Victorians adopts a design model of disability. The material culture of spectacles - largely gleaned from two collections at the Science Museum in London - reveals that the functional and non-functional aspects of Victorian spectacle design created a non-medical object, a multifaceted device able to perform and even normalise attitudes to partial sight.