1. The problem statement, all variables and given/known data Disparity is defined as [itex]\delta = \alpha - \beta[/itex]. Find [itex]\delta[/itex] in terms of interocular distance a, viewing distance D and d, e and f. http://img220.imageshack.us/img220/7576/43519392.jpg [Broken] 3. The attempt at a solution I'm not getting anywhere. Any tips to get me started?