Motion blindness
Currently, motion blindness is thought to be caused by a change to the regions of the brain that are responsible for sight. This change is usually a result of damage done to the brain, and affects the way the brain "decodes" visual information. It is possible that only "visual" motion processing is affected because this is done in a separate area of the brain, which is different from the area that does motion processing in general. The same can happen to the perception of color, that is the patient can have a form of color blindness, which is known as achromatopsia. Unlike most other forms of color blindness, which are caused by changes in the eye, this one is caused by changes in the brain.