Abstract
Purpose:
The aims of the present study were two-fold: 1. To develop and evaluate methods of utilizing a Mirametrix eye tracker to evaluate eccentric reading. 2. To compare eccentric viewing results with published anatomical descriptions of the fovea.
Methods:
Using binocular point of gaze (POG) data captured on Cartesian coordinates, eccentric viewing (EV) distances (by step approach in four directions), and eccentric reading (ER; by dynamically presenting and hiding words in the four directions), were evaluated in 3 subjects.
Results:
The average distances and standard deviations for EV were: inferior: 27.3mm ±2.92; superior: 28.0 ±2.67; right: 43.25 ±2.55; left: 43.92 ±2.76. ANOVA analysis provides sufficient evidence to suggest that the EV distances between three subjects are the same for inferior (p=0.99), superior (p=0.40), right (p=0.98), however, for left, it was the same for two of the three subjects (p=0.46). Analysis suggests that ER difficulty is the same for inferior versus superior (p=0.34), right versus left (p=0.65), but different for vertical versus horizontal meridian (p<0.001).
Conclusions:
EV was similar among subjects except when using left retina for one subject, which we believe shows the identification of the subject’s history of a binocular vision problem. The vertical to horizontal ratio (0.634) of our findings is similar to the anatomical ratio (0.667) of the fovea. The use of vertical directions during ER is similar in terms of distance and difficulty, as is the horizontal directions, but markedly differing between the two. Preliminary use of the Mirametrix eye tracker along with our methodology proves to be a useful research or clinical tool.
Keywords: 585 macula/fovea •
524 eye movements: recording techniques •
584 low vision