In this study we explore the possibility that by intensive treatment the period of amblyopia therapy can be shortened – i.e. made both more efficient and hopefully more effective. The purpose of the present study, the Randomized Occlusion Treatment of Amblyopia Study (ROTAS), is to compare two frequently employed patching regimens: ‘substantial’ (6 hrs/day) against ‘maximal’ (12 hrs/day) patching. Our experimental design incorporates objective occlusion monitoring and is able to discriminate the beneficial effect of refractive correction from that of occlusion. The study comprises three phases: ‘baseline’, ‘refractive adaptation’ and ‘occlusion.’ Our aim is to provide guidelines for patient management based, for the first time, on experimentally determined and statistically verifiable relationships between treatment and outcome.