This book argues that Chaucer challenges his culture's mounting obsession with vision through his varied constructions of masculinity. Because medieval theories of vision relied upon distinctions between active and passive seers and viewers, optical discourse had social and moral implications for gender difference in late fourteenth-century England. By exploring ocularity's equal dependence on invisibility, Chaucer offers men and women access to a vision of ''manhed,'' one that fragments a traditional gender binary by blurring its division between agency and passivity.