Binocular Vision Disorders

What is Binocular Vision?

The eyes each have six muscles that control their movement. There are three different cranial nerves, which control these muscles. To avoid seeing double, we must coordinate the movement of these twelve muscles in such a way that results in their being perfectly aligned. Like other muscles in the body, the ocular muscles have a resting position where they go to when we are not actively concentrating on anything. In their resting position, the eyes would ideally both point straight ahead when looking at a distance, and turn in slightly when looking at near. When not aligned properly, the eyes have to make significant corrections to maintain fusion and keep from seeing double. This requires energy from the brain that could be better spent processing and comprehending the information being viewed.


It is very important that a comprehensive vision examination be part of the interdisciplinary evaluation of all children who are failing to succeed in school.

Physical Signs and Symptoms

  • Frequent headaches or eye strain
  • Blurring of distance or near vision, particularly after reading or other close work
  • Avoidance of close work or other visually demanding tasks
  • Poor judgment of depth
  • Turning of an eye in or out, up or down
  • Tendency to cover or close on eye, or favor the vision in one eye
  • Difficulty following a moving target
  • Dizziness or motion sickness

Performance Problems

  • Poor reading comprehension
  • Difficulty copying from one place to another
  • Loss of place, repetition, and/or omission of words while reading
  • Difficulty changing focus from distance to near work and back
  • Poor posture when reading or writing
  • Poor handwriting
  • Can respond orally but can’t get the same information down on paper
  • Letter and word reversals
  • Difficulty judging sizes and shapes

3D Movies

3D movies are fun and exciting if you have 3D stereo vision. Click here for signs that a vision problem may be interfering with their enjoyment of 3D movies, TVs, etc.

Lazy Eye

Lazy eye is a lay (non-medical) term that typically carries two different meanings:

  1. An eye is turning in, out, up, or down (medically known as strabismus; see below)
  2. An eye that cannot see 20/20 even with the best glasses prescription (medically known as amblyopia; see below)

Having Vision Problems?

Contact the experts at Heartland Eye Consultants.