Figure 1From: Evidence for integrating eye health into primary health care in Africa: a health systems strengthening approach Overlap between Vision 2020 pillars, health systems building blocks and Ouagadougou key areas. Areas of overlap between the three pillars of the Vision 2020 initiative, [41, 62] and the six WHO health system building blocks, [53] and the nine key areas of Ouagadougou Declaration [63]. See online Additional file 1.Back to article page