"Wall-eyed" (divergent) stereograms will work fine for many people, but many others cannot diverge accurately enough to achieve fusion and stereopsis for these stereograms (e.g., people with convergence insufficiency; when diverging, they lose fusion and cannot regain it easily). This program also needs to also generate "cross-eyed" (convergent) stereograms. This is a simple thing to do -- just reverse the direction of the binocular disparities generated.