There are multiple ways that your eye/brain senses depth: binocular vision/vergence, lens focus, and relative correlated motion to name three. When these depth

There are multiple ways that your eye/brain senses depth: binocular vision/vergence, lens focus, and relative correlated motion to name three. When these depth cues don't match each other well, it is distracting and can cause fatigue or headaches after extended use.