ADDITIONAL CLASSIFICATIONS constant or intermittent-the frequency it occurs bilateral-both eyes converge or diverge at the same time unilateral-if it always involves the same eye alternating-when the turning is sometimes the right and other times the left eye from:American Optometric Association ADDITIONAL CLASSIFICATIONS • constant or intermittent—the frequency it occurs • bilateral—both eyes converge or diverge at the same time • unilateral—if it always involves the same eye • alternating—when the turning is sometimes the right and other times the left eye from: American Optometric Association