Blindness

How Blindness Affects the Brain

Brief Overview

As humans, we are very vision oriented. In the United States, an estimated 500,000 people are blind but medical advances have reduced some causes of blindness. Many researchers have done countless studies on vision impairment, prevention, and treatment. Often times, vision impairment can be prevented or the damage can be reduced.
Vision: Crash Course A&P #18
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Brain Structure

Research has confirmed that blindness causes structural change within the brain. Visual regions of the brain were smaller in volume in blind individuals than in sighted ones. However, non-vision areas such as the frontal lobe, grew larger in blind individuals suggesting that the brain is compensating for the smaller visual regions. If sight is lost at a young age, the area of the brain's corpus callosum that aids in the transmission of visual information between the two hemispheres of the brain was significantly different than that of sighted individuals or individuals that lost their sight at an older age. Additionally, regions outside the occipital lobe showed significant hypertrophy, there were deficits in the splenium, and hypertrophy in the isthmus.
Understanding Blindness and the Brain (Brian Wandell, Stanford University)
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Rerouting Brain Functions

Studies suggest that the brain has a predetermined genetic blueprint of the division of labor between brain regions. However, certain brain regions are able to take over functions that they were not destined to do. In individuals that are born blind, parts of the visual cortex are recruited for language processing. Parts of the visual cortex are divided up to perform different tasks as it is no longer being used to receive visual input.
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Medical Advances

Medical advances have made it possible for some individuals affected by blindness to be able to see again. Although most of the options available do not produce the same level of vision that sighted people are use to, improvements are being made every day and our treatment options and technology is consistently progressing.
Sheila Nirenberg: A prosthetic eye to treat blindness

Additional Information

For further information, please visit the following sites:


Brain Structure Changes Visualized in Early- and Late-Onset Blind Subjects

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2764825/


Parts of brain can switch functions: In people born blind, brain regions that usually process vision can tackle language

https://www.sciencedaily.com/releases/2011/02/110228163143.htm