This is a skill where both eyes aim simultaneously at the same visual target and work together equally and accurately as a coordinated team. Healthy binocular vision produces important visual perceptual skills as well, which are part of normal human vision.
A child is born with two eyes, but they must learn to use them together. Some children learn to do this properly while others do not.
Some conditions of a poor binocular system are:
- Tracking: the ability to move the eyes accurately in order to follow a moving target. Poor tracking greatly affects a person's ability to read.
- Fusion: the ability to use both eyes together at the same time. Poor fusion can result in blurred and/or double vision.
- Stereopis: binocular depth perception. Poor steropsis can result in limited or non-exitant 3D vision.