Eye movements from laboratory to life

Abstract

The manner in which we sample visual information from the world is constrained by the spatial and temporal sampling limits of the human eye. High acuity vision is restricted to the small central foveal region of the retina, which is limited to just a few degrees of visual angle in extent. Moreover, visual sampling is effectively limited to when the retinal image is relatively stabilised for periods of fixation (Erdmann and Dodge 1898), which last on average around 200—400 ms when viewing text, scenes or real environments (Land and Tatler 2009; Rayner 1998). It is clear from these severe spatiotemporal constraints on visual sampling that high acuity vision is a scarce resource and, like any scarce resource, it must be distributed carefully and appropriately for the current situation.