Premium
The impact of efferent oculomotor signals on size and distance perception
Author(s) -
Krastel H.,
Streuer A.,
Magerl W.,
Kubarko A.,
Jonas J.B.
Publication year - 2016
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2016.0532
Subject(s) - efferent , computer vision , object (grammar) , perception , artificial intelligence , computer science , position (finance) , optometry , mathematics , psychology , medicine , afferent , anatomy , finance , neuroscience , economics
Purpose To demonstrate the influence of efferent oculomotor signals on perceived size and distance of visual objects. Methods By fingertip, a pencil target has to be localized. The target is seen at 25 cm of distance on a 45° mirror mounted in front of the subject. With the finger behind the mirror, the subject is deprived from visual feedback. Observation is done either by naked eye or by looking through binocular prisms of 6 pdpt b.i. The fingertip estimate is recorded by an ElGuide ® ultrasound position control system (Zebris Medical, Isny, Germany). Results In first results, the prisms produced a mean 25% overestimation of target distance as recorded by fingertip position. The target appeared visibly larger. This prompted us to do trials with a minus −3 dpt lens instead of prisms, forcing the subject to overaccommodation. Hereby, the target appeared visibly smaller and more distant, but now, fingertip pointing ends up at reduced distance. Conclusions With reduced convergence the object appears larger and nearer. The distance of the object is over‐estimated by fingertip localization. Hyperaccommodation results in a smaller and more distant appearance of the object, but its fingertip distance is underestimated. Sense and purpose of these contradictory effects are not yet well understood. Visitors of the poster are encouraged to self experience.