The Occipital Lobes

The occipital lobes, also referred to as the visual cortex, are located below the parietal lobes and behind the temporal lobes. Anatomically, they are located in the back of the brain and occupy about 12% of the entire surface area of the neocortex of the brain.

Functionally the main job of the occipital lobes is to decode visual information, such as color, shape and movement. This is done by associating current visual perceptions with similar, stored memories. In turn, this permits the recognition and identification of objects. In the event of a traumatic brain injury (TBI) damage to the occipital lobes may result in complete or partial blindness. It can also result in a condition known as “visual agnosia” which is an impairment of the ability to recognize objects, and sometimes causes visual hallucinations.

One’s field of vision is comprised of the entire scope of a person’s vision. It consists of a combination of one’s central and peripheral vision. The visual field is directly imaged onto the retina of the eye by the optics of the eye. The optics of the eye consist of the following structures:

1. The lens. The lens of the eye is not round; it is thicker in the center than at the edges. Therefore, it forms an inverted image on the retina. The retina is located at the back of the eye. The image on the retina is formed by two lenses. These are the cornea, which is a converging lens, the focal length of which is fixed, and the eye-lens, the focal length of which can be varied by changing its shape.

2. The iris and the pupil. The iris is circular and its color defines the color of a person’s eyes, although the color lacks any visual meaning. The central opening of the iris is the pupil. The diameter of the opening of changes in relation to the ambient level, such that it is smaller in bright light than in the dark.

3. The retina. The retina is the optically sensitive part of the eye and has the greatest relationship to brain function. This is because it is the screen on which images are formed. It is connected directly to the brain by the optic nerve. The retina consists of more than 100 million sensors that are commonly called rods and cones. The rods are more sensitive to low light levels whereas the cones operate at higher light levels and control the ability to perceive colors. Information from the retina leaves the eye by the optic nerve, which in turn leads to a structure known as the “optic chiasm.” Since all external sensory data to the brain is crossed, that from the right eye goes to the left hemisphere of the brain, and that from the left eye goes to the right hemisphere.

There also exists what are sometimes called “streams” in the function of the occipital lobes. Broadly, this refers to aspects of vision and, consequently, cognition of visual information. For example, two main ones are thought to be the occipito-temporal pathway and the occipito-parietal pathway. The former is hypothesized to be involved with object recognition, whereas the latter is thought to be involved with spatial vision and visually guided action toward objects.

A stroke is sometimes referred to as a “brain attack.” It occurs when the blood, which brings oxygen to the brain, stops flowing. As a result, brain cells die. Strokes often affect one or both of the occipital lobes. Vision loss or vision impairment can be either a symptom or result of a stroke. Several types of vision loss may result from occipital lobe strokes. Homonymous hemianopia is the most common type and is loss of half the visual field in each eye. Other types include loss of a quarter of the field of vision known as “homonymous quadrantanopia,” and an island-like area of blindness that is called “scotoma.”

The focus of occipital lobe-related vision loss, whether caused by occipital lobe injury or occipital lobe stroke is to maximize visual function by the use of varied modalities. At NeuLife, we gear those modalities to the severity of the client’s dysfunction, the nature of the injury and to the client’s goals and desires. For example, some clients have a primary desire to read again, while others have more severe challenges in processing information and cognition.

The multidisciplinary team of professionals at NeuLife use integrated forms of assessment, rehabilitation and client education, all with the goal of returning each client to his or her maximum level of well being and function.

NeuLife’s philosophy is that healing, wellness and personal fulfillment are best accomplished in a positive and uplifting therapeutic environment where caring staff encourage, assist and support each client so that he or she may achieve specific goals. NeuLife believes personal fulfillment is equally as important as goals to increase function and independence. NeuLife’s multidisciplinary team seeks to achieve, for all of its clients, maximized, sustained outcomes that exceed the expectations of all persons served. Those referred to NeuLife may stay for any established period of time, whether for short-term, long-term or respite care.

NeuLife, in Mount Dora, Florida, is a fully accessible specialized residential post-acute program providing specialized rehabilitation to individuals diagnosed with traumatic brain injury (TBI), spinal cord injury (SCI), traumatic amputations and other catastrophic injuries.

2725 Robie Avenue
Mount Dora, Florida 32757
Call: 800.626.3836
Email: [email protected]
Visit: NeuLifeRehab.com