first-degree fusion

The ability to superimpose or fuse dissimilar targets or images seen by the two eyes into a single, unified percept. It involves cortical processing of binocular visual input to combine the different views from each eye into one coherent 3D image. First-degree fusion is a fundamental aspect of binocular vision and stereopsis, allowing depth perception. Disruptions can lead to diplopia or suppression, and it is tested by presenting different targets to each eye.