scotoma
noun
sco·to·ma skə-ˈtō-mə 
plural scotomas or scotomata skə-ˈtō-mə-tə
: a spot in the visual field in which vision is absent or deficient
Example Sentences
Recent Examples on the Web Symptoms may be mild and temporary, or leave some viewers with blind spots called scotomas. 
Bruce Henderson, charlotteobserver, 12 July 2017
Bruce Henderson, charlotteobserver, 12 July 2017 Word History
Etymology
New Latin, from Medieval Latin, dimness of vision, from Greek skotōmat-, skotōma, from skotoun to darken, from skotos
First Known Use
1822, in the meaning defined above
Medical Definition
scotoma
noun
sco·to·ma skə-ˈtō-mə
plural scotomas or scotomata -mət-ə
: a spot in the visual field in which vision is absent or deficient