Fig. 2.

The dichoptic custom-made Unreal Tournament video game. (A) Game group participants used a mirror stereoscope to achieve alignment and play the dichoptic game. (B) Nonius lines appearing at the beginning of a training session, to allow for alignment and fusion of the two eyes. Participants viewed this through a stereoscope, when each eye receives half a cross. Participants were asked to align the two images until they perceived a complete cross in the center. (C) A screen shot of the actual game while being played by an amblyopic participant. At the start of each training session, participants adjust the alpha level of the image seen by the non-amblyopic eye (NAE) in order to overcome suppression and to achieve fusion. The set alpha level is then used to play the game, so that the amblyopic eye (AE) image is usually brighter than the NAE image. Green and red targets (see cross hairs) are also aligned prior to game play. In addition, an adaptive Gabor discrimination task is embedded in the scene viewed by the AE (gray square in center of left image). Participants were instructed to play the action game, by shooting enemies or bots as quickly as possible. A demo of the game can be seen at: http://www.youtube.com/watch?v_71RML96XxCI.