See also
Near-sightedness
Far-sightedness

References
External links
 The dictionary definition of astigmatism at Wiktionary
 Media related to Astigmatism (eye) at Wikimedia Commons
Astigmatism at Curlie
Methadone, Substance Abuse and Mental Health Services Administration, U.S. Department of Health and Human Services
Tapering off of methadone maintenance
DE patent 711069, Dr Max Bockmuehl & Dr Gustav Ehrhart, "Verfahren zur Darstellung von basischen Estern", published 1941-09-25, issued 1941-09-25,  assigned to IG Farbenindustrie AG