August 1st

Eye Physiology  ⁄  Binocular Vision

Binocular vision is an incorporated activity of the sensory and motor systems of both eyes. When the eyes are looking at an object, the images appear on the retinas of both eyes. Two monocular images fuse to create the single visual image in a process called fusion. Binocular vision increases the brightness of the visual object and visual acuity by about 20%.

When the medial parts of the visual fields of each eye fuse, a common visual field appears where binocular fixation is possible. In the diagram below, the visual field of the left eye is shown with horizontal lines, and the visual field of the right eye is shown with vertical lines. The middle common part is the binocular visual field. The width of the binocular field is about 115 degrees.


Fusion requires some conditions. The first is that the monocular image in each eye is located equally in relation to the foveola, which is situated in the center of the macula. So, for binocular vision, it is necessary to use central fixation of eyesight. The second condition is that monocular images on both retinas are the same size.

In binocular vision, in most cases one eye is driving (leading), and the other eye is driven. In some cases, called ambidexterity, the both eyes participate in vision equally.

The simplest way to identify the leading eye is to position yourself in a half-turn towards the monitor, with your head turned first towards the right side, and then towards the left side. It will be more convenient for you to look when the leading eye is closer to the monitor. For example, if your leading eye is right, it is more convenient for you to look at the monitor while sitting in a half turn with the right side of your face towards the monitor. In the following exercise, I will tell you how to define the leading eye through double imaging and fusion of images.

Take care of your eyes. Get rid of myopia the natural way.

Dr. Arkadiy Davydov.

4 Responses

  1. Kathy Kuchinos:

    07.10.2013 at 21:06 #

    Doctor, I have been wearing glasses and contacts since the age of 5 and very nearsighted. In June in planning for cataract surgery I could not wear my contacts for 6 weeks. My vision was fine for arms length with my glasses but after 3-4 feet I would see double. It appeared that the left eye was pulling the object outward and down to the left. After cataract surgery I was hoping for improvement with the correction of astigmatism in my left eye but it has not. My right eye sees distance better and my left sees computer screen better. I still need readers. The left eye still pulls the object to the left and down at distance. I am not sure if I have a convergence or divergence problem. What exercises would you recommend?

  2. Doc:

    10.10.2013 at 23:16 #

    Kathy, in my opinion the eye exercises can’t help you after a cataract surgery

  3. Miriam:

    04.11.2013 at 00:52 #

    Hello. My husband had radiation treatment to his head for left ethmoidal sinus tumor 10 yrs ago. He now developed weakness of the left lateral rectus with diplopia on left gaze which increased from 6-10 PD in the last year. He has no double vision straight ahead. His MRI is normal. zi did notice recently he prefers a slight left head turn. I am a neuro-ophthalmologist, but I am at a loss of how to practically help him. I see that your excercises are primarily for myopia, but are there any exercises you can recommend for his type of problem?

  4. Doc:

    04.11.2013 at 15:25 #

    Miriam, unfortunately I haven’t any ideas

Leave a Reply


Recent Posts


Enter your email:

Delivered by FeedBurner