Figure 1.

Stimuli examples. (A) Example stimuli for the computerized Amsler grid task. The left panel shows the blank grid (i.e., how it appeared when the participant was fixating centrally), with the green circular disk representing the location of fixation as measured by the eye tracker. The right panel shows the gaze shifted away from central fixation, displaying the series of white drawn lines that depict the described distortion by the participant. To avoid confusion, the rendition of distortion was only visible when the participant was not fixating centrally. (B) Stimuli for the square completion task. The left panel depicts the first set of dots, a fixed green dot and three adjustable white dots, which the observer was required to move to create the four corners of a notional square. The center panel shows the set of four orange-colored bisecting dots that the observer was required to move to midpoints of the sides of the square. The right panel shows an example of a square created by one participant who completed four trials of both the corner and midpoint portion of the task. (C) Stimuli for the dichoptic pointing task. The left panel shows the moveable green crosshairs that were displayed only to the affected eye or a randomly chosen eye of the controls. The central panel shows a red target disk that displayed only to the less affected eye, or the other eye of controls. The right panel shows the combined cyclopean percept when the participant was wearing shutter glasses. A 1/F noise background was used to mask crosstalk.