Dictionary. Word

Saccade
noun (usually saccades) technical
a rapid movement of the eye between fixation points.
Origin: early 18th century (in the sense 'jerking movement'): from French, literally 'violent pull', from Old French saquer 'to pull'
Source: oxforddictionaries.com

Innocent Eye 
That ‘there is no innocent eye’ is one of the central propositions of E.H.Gombrich's Art and Illusion and a mantra that has played an immense role in art-historical and aesthetic scholarship for the past fifty years. It is also commonly thought to stand in a difficult relationship with Gombrich's rejection of the conventionalist understanding of human visuality.
Source: Wikipedia.org