M. Menozzi et al., DIRECTION OF GAZE AND COMFORT - DISCOVERING THE RELATION FOR THE ERGONOMIC OPTIMIZATION OF VISUAL TASKS, Ophthalmic & physiological optics, 14(4), 1994, pp. 393-399
Perceived exertion caused by the extraocular muscles was assessed as a
function of the direction of gaze and recorded in 114 subjects using
a psychometric method. The results confirm statements in the literatur
e that maximum comfort is achieved when gaze is aimed downwards. We fo
und no correlations between perceived exertion and age or viewing dist
ance. The relationship is relevant to ergonomics, for example in lens
fitting and workplace layout.