<p><strong>Short answer</strong>  </p>

<ul>
<li>The <em>corpus callosum</em> is not necessary for low-level visual processing;</li>
<li>Both eyes project to both hemispheres; the left visual hemifield of both eyes is projected to the left hemisphere, the right hemifield to the right. </li>
</ul>

<p><strong>Background</strong><br>
The site where the right and left visual hemifields are split occurs in the <a href="https://radiopaedia.org/articles/optic-chiasm" rel="nofollow noreferrer"><em>optic chiasm</em></a>. This structure is different from the major highway between both hemispheres, namely the <em><a href="http://cnsvp.stanford.edu/atlas/corpus_callosum.html" rel="nofollow noreferrer">corpus callosum</a></em> (Fig. 1). Hence, your question...</p>

<blockquote>
  <p>[I]f a person has only [functionality in the] left eye[,] and [..]their <em>corpus callosum</em> [is severed], would they be effectively blind[,] since the left brain won't receive any visual stimuli?</p>
</blockquote>

<p>...can be answered with <strong><em>no</em></strong>, as both eyes will still transmit their input to the visual centers in the brain (Fig. 1). In fact, when one eye is not functional, the fieldof view will still be nearly complete, as both hemifields of the one remaining retina is projected to both cortices (Fig. 2). </p>

<p>The function that is effectively lost when there is only one eye left, is depth perception; the use of both eyes, and the fact that they are slightly offset, allows us to see depth, using binocular vision through a process referred to as <a href="https://en.wikipedia.org/wiki/Binocular_disparity" rel="nofollow noreferrer"><strong>binocular disparity</strong></a>. </p>

<p><a href="https://i.sstatic.net/lmxbY.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/lmxbY.jpg" alt="brain"></a><br>
<sup>Fig. 1. Mid-saggital section through the brain. source: <a href="https://www.studocu.com/en/document/university-of-birmingham/medical-science-and-society/lecture-notes/threats-and-defence-anatomy-week-2/1950648/view" rel="nofollow noreferrer">Studoku</a></sup></p>

<p><a href="https://i.sstatic.net/qc66o.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/qc66o.jpg" alt="visual pathway"></a><br>
<sup>Fig. 2. Visual pathway. source: <a href="https://www.brainrecoveryproject.org/for-parents/brain-surgeries-to-stop-seizures/hemispherectomy/functional-outcomes/vision-hemispherectomy-occipital-lobectomy-tpo-disconnection/1420_optical_fields/" rel="nofollow noreferrer">The Brain Recovery Project</a></sup></p>

CC BY-SA 4.0
2018-11-19T11:09:36.867Z
Thanks for the detailed answer!
Prathamesh Kulkarni
CC BY-SA 4.0
2018-11-16T14:30:51.663Z
2019-01-09T08:17:07.903Z
2019-01-09T08:17:07.903Z
AliceD
<p>I am just beginning to learn psychology and came across concept of split brain. I was wondering if a person has only left eye working and has their corpus callosum cut, would they be effectively blind since the left brain won't receive any visual stimuli?</p>

<neuroscience><perception><vision><neurophysiology><neuroanatomy>
Unilateral vision in split brain subjects
Prathamesh Kulkarni
# Unilateral vision in split brain subjects

(Asked by: username_0 on 2018-11-16)

I am just beginning to learn psychology and came across concept of split brain. I was wondering if a person has only left eye working and has their corpus callosum cut, would they be effectively blind since the left brain won't receive any visual stimuli?

**Tags:** neuroscience, perception, vision, neurophysiology, neuroanatomy


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## 1 answers

### Answer by username_1 on 2018-11-16. Score: 2 | Accepted answer

**Short answer**

* The *corpus callosum* is not necessary for low-level visual processing;
* Both eyes project to both hemispheres; the left visual hemifield of both eyes is projected to the left hemisphere, the right hemifield to the right.

**Background**  
The site where the right and left visual hemifields are split occurs in the [*optic chiasm*](https://radiopaedia.org/articles/optic-chiasm). This structure is different from the major highway between both hemispheres, namely the *[corpus callosum](http://cnsvp.stanford.edu/atlas/corpus_callosum.html)* (Fig. 1). Hence, your question...

> [I]f a person has only [functionality in the] left eye[,] and [..]their *corpus callosum* [is severed], would they be effectively blind[,] since the left brain won't receive any visual stimuli?

...can be answered with ***no***, as both eyes will still transmit their input to the visual centers in the brain (Fig. 1). In fact, when one eye is not functional, the fieldof view will still be nearly complete, as both hemifields of the one remaining retina is projected to both cortices (Fig. 2).

The function that is effectively lost when there is only one eye left, is depth perception; the use of both eyes, and the fact that they are slightly offset, allows us to see depth, using binocular vision through a process referred to as [**binocular disparity**](https://en.wikipedia.org/wiki/Binocular_disparity).

[![brain](https://i.sstatic.net/lmxbY.jpg)](https://i.sstatic.net/lmxbY.jpg)  
Fig. 1. Mid-saggital section through the brain. source: [Studoku](https://www.studocu.com/en/document/university-of-birmingham/medical-science-and-society/lecture-notes/threats-and-defence-anatomy-week-2/1950648/view)

[![visual pathway](https://i.sstatic.net/qc66o.jpg)](https://i.sstatic.net/qc66o.jpg)  
Fig. 2. Visual pathway. source: [The Brain Recovery Project](https://www.brainrecoveryproject.org/for-parents/brain-surgeries-to-stop-seizures/hemispherectomy/functional-outcomes/vision-hemispherectomy-occipital-lobectomy-tpo-disconnection/1420_optical_fields/)

> **Comments:**
> **username_0**: Thanks for the detailed answer!  

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