Your brain does the work of intelligently putting together the sharpest parts from each eye's view, but the two eyes see slightly different things, and that makes it harder to judge distances binocularly.
O cérebro faz o trabalho  inteligente de juntar as partes mais nítidas de cada visão, mas os dois olhos veem as coisas levemente diferentes, e isso dificulta avaliar as distâncias binoculares.