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<meta name="robots" content="INDEX,FOLLOW,NOARCHIVE" /><meta name="citation_inbook_title" content="Webvision: The Organization of the Retina and Visual System [Internet]" /><meta name="citation_title" content="The Perception of Depth" /><meta name="citation_publisher" content="University of Utah Health Sciences Center" /><meta name="citation_date" content="2007/06/06" /><meta name="citation_author" content="Michael Kalloniatis" /><meta name="citation_author" content="Charles Luu" /><meta name="citation_pmid" content="21413376" /><meta name="citation_fulltext_html_url" content="https://www.ncbi.nlm.nih.gov/books/NBK11512/" /><link rel="schema.DC" href="http://purl.org/DC/elements/1.0/" /><meta name="DC.Title" content="The Perception of Depth" /><meta name="DC.Type" content="Text" /><meta name="DC.Publisher" content="University of Utah Health Sciences Center" /><meta name="DC.Contributor" content="Michael Kalloniatis" /><meta name="DC.Contributor" content="Charles Luu" /><meta name="DC.Date" content="2007/06/06" /><meta name="DC.Identifier" content="https://www.ncbi.nlm.nih.gov/books/NBK11512/" /><meta name="description" content="Stereopsis refers to our ability to appreciate depth, that is, the ability to distinguish the relative distance of objects with an apparent physical displacement between the objects. It is possible to appreciate the relative location of objects using one eye (monocular cues). However, it is the lateral displacement of the eyes that provides two slightly different views of the same object (disparate images) and allows acute stereoscopic depth discrimination." /><meta name="og:title" content="The Perception of Depth" /><meta name="og:type" content="book" /><meta name="og:description" content="Stereopsis refers to our ability to appreciate depth, that is, the ability to distinguish the relative distance of objects with an apparent physical displacement between the objects. It is possible to appreciate the relative location of objects using one eye (monocular cues). However, it is the lateral displacement of the eyes that provides two slightly different views of the same object (disparate images) and allows acute stereoscopic depth discrimination." /><meta name="og:url" content="https://www.ncbi.nlm.nih.gov/books/NBK11512/" /><meta name="og:site_name" content="NCBI Bookshelf" /><meta name="og:image" content="https://www.ncbi.nlm.nih.gov/corehtml/pmc/pmcgifs/bookshelf/thumbs/th-webvision-lrg.png" /><meta name="twitter:card" content="summary" /><meta name="twitter:site" content="@ncbibooks" /><meta name="bk-non-canon-loc" content="/books/n/webvision/ch30kalldepth/" /><link rel="canonical" href="https://www.ncbi.nlm.nih.gov/books/NBK11512/" /><link rel="stylesheet" href="/corehtml/pmc/css/figpopup.css" type="text/css" media="screen" /><link rel="stylesheet" href="/corehtml/pmc/css/bookshelf/2.26/css/books.min.css" type="text/css" /><link rel="stylesheet" href="/corehtml/pmc/css/bookshelf/2.26/css/books_print.min.css" type="text/css" media="print" /><style type="text/css">p a.figpopup{display:inline !important} .bk_tt {font-family: monospace} .first-line-outdent .bk_ref {display: inline} .body-content h2, .body-content .h2 {border-bottom: 1px solid #97B0C8} .body-content h2.inline {border-bottom: none} a.page-toc-label , .jig-ncbismoothscroll a {text-decoration:none;border:0 !important} .temp-labeled-list .graphic {display:inline-block !important} .temp-labeled-list img{width:100%}</style><script type="text/javascript" src="/corehtml/pmc/js/jquery.hoverIntent.min.js"> </script><script type="text/javascript" src="/corehtml/pmc/js/common.min.js?_=3.18"> </script><script type="text/javascript" src="/corehtml/pmc/js/large-obj-scrollbars.min.js"> </script><script type="text/javascript">window.name="mainwindow";</script><script type="text/javascript" src="/corehtml/pmc/js/bookshelf/2.26/book-toc.min.js"> </script><script type="text/javascript" src="/corehtml/pmc/js/bookshelf/2.26/books.min.js"> </script><meta name="book-collection" content="NONE" />
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<div class="pre-content"><div><div class="bk_prnt"><p class="small">NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.</p><p>Kolb H, Fernandez E, Jones B, et al., editors. Webvision: The Organization of the Retina and Visual System [Internet]. Salt Lake City (UT): University of Utah Health Sciences Center; 1995-. </p></div><div class="iconblock clearfix whole_rhythm no_top_margin bk_noprnt"><a class="img_link icnblk_img" title="Table of Contents Page" href="/books/n/webvision/"><img class="source-thumb" src="/corehtml/pmc/pmcgifs/bookshelf/thumbs/th-webvision-lrg.png" alt="Cover of Webvision" height="100px" width="80px" /></a><div class="icnblk_cntnt eight_col"><h2>Webvision: The Organization of the Retina and Visual System [Internet].</h2><a data-jig="ncbitoggler" href="#__NBK11512_dtls__">Show details</a><div style="display:none" class="ui-widget" id="__NBK11512_dtls__"><div>Kolb H, Fernandez E, Jones B, et al., editors.</div><div>Salt Lake City (UT): <a href="http://webvision.med.utah.edu/" ref="pagearea=page-banner&targetsite=external&targetcat=link&targettype=publisher">University of Utah Health Sciences Center</a>; 1995-.</div></div><div class="half_rhythm"><ul class="inline_list"><li style="margin-right:1em"><a class="bk_cntns" href="/books/n/webvision/">Contents</a></li></ul></div><div class="bk_noprnt"><form method="get" action="/books/n/webvision/" id="bk_srch"><div class="bk_search"><label for="bk_term" class="offscreen_noflow">Search term</label><input type="text" title="Search this book" id="bk_term" name="term" value="" data-jig="ncbiclearbutton" /> <input type="submit" class="jig-ncbibutton" value="Search this book" submit="false" style="padding: 0.1em 0.4em;" /></div></form></div></div><div class="icnblk_cntnt two_col"><div class="pagination bk_noprnt"><a class="active page_link prev" href="/books/n/webvision/ch29space_perceptio/" title="Previous page in this title">< Prev</a><a class="active page_link next" href="/books/n/webvision/brainvisual/" title="Next page in this title">Next ></a></div></div></div></div></div>
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<div class="main-content lit-style" itemscope="itemscope" itemtype="http://schema.org/CreativeWork"><div class="meta-content fm-sec"><h1 id="_NBK11512_"><span class="title" itemprop="name">The Perception of Depth</span></h1><p class="contrib-group"><span itemprop="author">Michael Kalloniatis</span> and <span itemprop="author">Charles Luu</span>.</p><a data-jig="ncbitoggler" href="#__NBK11512_ai__" style="border:0;text-decoration:none">Author Information and Affiliations</a><div style="display:none" class="ui-widget" id="__NBK11512_ai__"><p class="contrib-group"><h4>Authors</h4><span itemprop="author">Michael Kalloniatis</span> and <span itemprop="author">Charles Luu</span>.</p><h4>Affiliations</h4><div class="affiliation"><sup>1</sup>
|
||
Department of Optometry and Vision Sciences University of Melbourne,
|
||
Australia
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||
</div></div><p class="small">Created: <span itemprop="datePublished">May 1, 2005</span>; Last Update: <span itemprop="dateModified">June 6, 2007</span>.</p></div><div class="jig-ncbiinpagenav body-content whole_rhythm" data-jigconfig="allHeadingLevels: ['h2'],smoothScroll: false" itemprop="text"><div id="ch30kalldepth.Stereopsis"><h2 id="_ch30kalldepth_Stereopsis_">Stereopsis</h2><p>Stereopsis refers to our ability to appreciate depth, that is, the ability to
|
||
distinguish the relative distance of objects with an apparent physical displacement
|
||
between the objects. It is possible to appreciate the relative location of objects
|
||
using one eye (monocular cues). However, it is the lateral displacement of the eyes
|
||
that provides two slightly different views of the same object (disparate images) and
|
||
allows acute stereoscopic depth discrimination.</p></div><div id="ch30kalldepth.Monocular_Cues"><h2 id="_ch30kalldepth_Monocular_Cues_">Monocular Cues</h2><p>Several strong monocular cues allow relative distance and depth to be judged. These
|
||
monocular cues include:</p><ul><li id="A4197" class="half_rhythm"><div>relative size</div></li><li id="A4198" class="half_rhythm"><div>interposition</div></li><li id="A4199" class="half_rhythm"><div>linear perspective</div></li><li id="A4200" class="half_rhythm"><div>aerial perspective</div></li><li id="A4201" class="half_rhythm"><div>light and shade</div></li><li id="A4202" class="half_rhythm"><div>monocular movement parallax</div></li></ul><div id="ch30kalldepth.Relative_Size"><h3>Relative Size</h3><p>Retinal image size allow us to judge distance based on our past and present
|
||
experience and familiarity with similar objects. As the car drives away, the
|
||
retinal image becomes smaller and smaller. We interpret this as the car getting
|
||
further and further away. This is referred to as size constancy. A retinal image
|
||
of a small car is also interpreted as a distant car (<a class="figpopup" href="/books/NBK11512/figure/ch30kalldepth.F1/?report=objectonly" target="object" rid-figpopup="figch30kalldepthF1" rid-ob="figobch30kalldepthF1">Fig. 1</a>).</p><div class="iconblock whole_rhythm clearfix ten_col fig" id="figch30kalldepthF1" co-legend-rid="figlgndch30kalldepthF1"><a href="/books/NBK11512/figure/ch30kalldepth.F1/?report=objectonly" target="object" title="Figure 1" class="img_link icnblk_img figpopup" rid-figpopup="figch30kalldepthF1" rid-ob="figobch30kalldepthF1"><img class="small-thumb" src="/books/NBK11512/bin/kalldepthf1.gif" src-large="/books/NBK11512/bin/kalldepthf1.jpg" alt="Figure 1. Relative size." /></a><div class="icnblk_cntnt" id="figlgndch30kalldepthF1"><h4 id="ch30kalldepth.F1"><a href="/books/NBK11512/figure/ch30kalldepth.F1/?report=objectonly" target="object" rid-ob="figobch30kalldepthF1">Figure 1</a></h4><p class="float-caption no_bottom_margin">Relative size. A retinal image of a small car is considered to be
|
||
distant. </p></div></div></div><div id="ch30kalldepth.Interposition"><h3>Interposition</h3><p>Interposition cues occur when there is overlapping of objects. The overlapped
|
||
object is considered further away (<a class="figpopup" href="/books/NBK11512/figure/ch30kalldepth.F2/?report=objectonly" target="object" rid-figpopup="figch30kalldepthF2" rid-ob="figobch30kalldepthF2">Fig. 2</a>).</p><div class="iconblock whole_rhythm clearfix ten_col fig" id="figch30kalldepthF2" co-legend-rid="figlgndch30kalldepthF2"><a href="/books/NBK11512/figure/ch30kalldepth.F2/?report=objectonly" target="object" title="Figure 2" class="img_link icnblk_img figpopup" rid-figpopup="figch30kalldepthF2" rid-ob="figobch30kalldepthF2"><img class="small-thumb" src="/books/NBK11512/bin/kalldepthf2.gif" src-large="/books/NBK11512/bin/kalldepthf2.jpg" alt="Figure 2. Interposition." /></a><div class="icnblk_cntnt" id="figlgndch30kalldepthF2"><h4 id="ch30kalldepth.F2"><a href="/books/NBK11512/figure/ch30kalldepth.F2/?report=objectonly" target="object" rid-ob="figobch30kalldepthF2">Figure 2</a></h4><p class="float-caption no_bottom_margin">Interposition. The blue circle is reported to be closer because it
|
||
overlaps the red circle. </p></div></div></div><div id="ch30kalldepth.Linear_Perspective"><h3>Linear Perspective</h3><p>When objects of known distance subtend a smaller and smaller angle, it is
|
||
interpreted as being further away. Parallel lines converge with increasing
|
||
distance such as roads, railway lines, electric wires, etc. (<a class="figpopup" href="/books/NBK11512/figure/ch30kalldepth.F3/?report=objectonly" target="object" rid-figpopup="figch30kalldepthF3" rid-ob="figobch30kalldepthF3">Fig.
|
||
3</a>).</p><div class="iconblock whole_rhythm clearfix ten_col fig" id="figch30kalldepthF3" co-legend-rid="figlgndch30kalldepthF3"><a href="/books/NBK11512/figure/ch30kalldepth.F3/?report=objectonly" target="object" title="Figure 3" class="img_link icnblk_img figpopup" rid-figpopup="figch30kalldepthF3" rid-ob="figobch30kalldepthF3"><img class="small-thumb" src="/books/NBK11512/bin/kalldepthf3.gif" src-large="/books/NBK11512/bin/kalldepthf3.jpg" alt="Figure 3. Linear perspective." /></a><div class="icnblk_cntnt" id="figlgndch30kalldepthF3"><h4 id="ch30kalldepth.F3"><a href="/books/NBK11512/figure/ch30kalldepth.F3/?report=objectonly" target="object" rid-ob="figobch30kalldepthF3">Figure 3</a></h4><p class="float-caption no_bottom_margin">Linear perspective. Parallel lines, such as railway lines, converge
|
||
with increasing distance. </p></div></div></div><div id="ch30kalldepth.Aerial_Perspective"><h3>Aerial Perspective</h3><p>Relative color of objects gives us some clues to their distance. Because of the
|
||
scattering of blue light in the atmosphere, creating a "wall" of blue light,
|
||
distance objects appear more blue (<a class="figpopup" href="/books/NBK11512/figure/ch30kalldepth.F4/?report=objectonly" target="object" rid-figpopup="figch30kalldepthF4" rid-ob="figobch30kalldepthF4">Fig. 4</a>). Thus, distant mountains
|
||
appear blue. Contrast of objects also provide clues to their distance. When the
|
||
scattering of light blurs the outlines of objects, the object is perceived as
|
||
distant. Mountains are perceived to be closer when the atmosphere is clear.</p><div class="iconblock whole_rhythm clearfix ten_col fig" id="figch30kalldepthF4" co-legend-rid="figlgndch30kalldepthF4"><a href="/books/NBK11512/figure/ch30kalldepth.F4/?report=objectonly" target="object" title="Figure 4" class="img_link icnblk_img figpopup" rid-figpopup="figch30kalldepthF4" rid-ob="figobch30kalldepthF4"><img class="small-thumb" src="/books/NBK11512/bin/kalldepthf4.gif" src-large="/books/NBK11512/bin/kalldepthf4.jpg" alt="Figure 4. Aerial perspective." /></a><div class="icnblk_cntnt" id="figlgndch30kalldepthF4"><h4 id="ch30kalldepth.F4"><a href="/books/NBK11512/figure/ch30kalldepth.F4/?report=objectonly" target="object" rid-ob="figobch30kalldepthF4">Figure 4</a></h4><p class="float-caption no_bottom_margin">Aerial perspective. Mountains in the distance appear more blue. </p></div></div></div><div id="ch30kalldepth.Light_and_Shade"><h3>Light and Shade</h3><p>Highlights and shadows can provide information about an object's dimensions and
|
||
depth (<a class="figpopup" href="/books/NBK11512/figure/ch30kalldepth.F5/?report=objectonly" target="object" rid-figpopup="figch30kalldepthF5" rid-ob="figobch30kalldepthF5">Fig. 5</a>). Because our visual system
|
||
assumes that the light comes from above, a totally different perception is
|
||
obtained if the image is viewed upside down.</p><div class="iconblock whole_rhythm clearfix ten_col fig" id="figch30kalldepthF5" co-legend-rid="figlgndch30kalldepthF5"><a href="/books/NBK11512/figure/ch30kalldepth.F5/?report=objectonly" target="object" title="Figure 5" class="img_link icnblk_img figpopup" rid-figpopup="figch30kalldepthF5" rid-ob="figobch30kalldepthF5"><img class="small-thumb" src="/books/NBK11512/bin/kalldepthf5.gif" src-large="/books/NBK11512/bin/kalldepthf5.jpg" alt="Figure 5. Highlights and shadows provide information about depth." /></a><div class="icnblk_cntnt" id="figlgndch30kalldepthF5"><h4 id="ch30kalldepth.F5"><a href="/books/NBK11512/figure/ch30kalldepth.F5/?report=objectonly" target="object" rid-ob="figobch30kalldepthF5">Figure 5</a></h4><p class="float-caption no_bottom_margin">Highlights and shadows provide information about depth. </p></div></div></div><div id="ch30kalldepth.Monocular_Movement_P"><h3>Monocular Movement Parallax</h3><p>When our heads move from side to side, objects at different distances move at a
|
||
different relative velocity. Closer objects move "against" the direction of head
|
||
movement and farther objects move "with" the direction of head movement.</p></div></div><div id="ch30kalldepth.Binocular_Cues"><h2 id="_ch30kalldepth_Binocular_Cues_">Binocular Cues</h2><p>Stereopsis is an important binocular cue to depth perception. Stereopsis cannot occur
|
||
monocularly and is due to binocular retinal disparity within Panum's fusional space.
|
||
Stereopsis is the perception of depth produced by binocular retinal disparity.
|
||
Therefore, two objects stimulate disparate (non-corresponding) retinal points within
|
||
Panum's fusional area.</p><p><b>Fusion</b> describes the neural process that brings the retinal images in
|
||
the two eyes to form one single image. Fusion occurs to allow single binocular
|
||
vision. Fusion takes place when the objects are the same. When the objects are
|
||
different, suppression, superimposition, or binocular ("retinal") rivalry may occur.
|
||
Suppression occurs to eliminate one image to prevent confusion. Superimposition
|
||
results in one image presented on top of the other image. Binocular rivalry
|
||
describes alternating suppression of the two eyes, resulting in alternating
|
||
perception of the two images. This usually occurs when lines that are presented to
|
||
the two eyes differ in orientation, length, or thickness. An example of binocular
|
||
rivalry occurs when one eye is presented with a horizontal line and the other eye is
|
||
presented with a vertical line. Binocular rivalry occurs at the intersection of the
|
||
lines, and some suppression also exists (<a class="figpopup" href="/books/NBK11512/figure/ch30kalldepth.F6/?report=objectonly" target="object" rid-figpopup="figch30kalldepthF6" rid-ob="figobch30kalldepthF6">Fig. 6</a>).</p><div class="iconblock whole_rhythm clearfix ten_col fig" id="figch30kalldepthF6" co-legend-rid="figlgndch30kalldepthF6"><a href="/books/NBK11512/figure/ch30kalldepth.F6/?report=objectonly" target="object" title="Figure 6" class="img_link icnblk_img figpopup" rid-figpopup="figch30kalldepthF6" rid-ob="figobch30kalldepthF6"><img class="small-thumb" src="/books/NBK11512/bin/kalldepthf6.gif" src-large="/books/NBK11512/bin/kalldepthf6.jpg" alt="Figure 6. (a) Binocular rivalry can be demonstrated by placing a pen between yourself and the screen." /></a><div class="icnblk_cntnt" id="figlgndch30kalldepthF6"><h4 id="ch30kalldepth.F6"><a href="/books/NBK11512/figure/ch30kalldepth.F6/?report=objectonly" target="object" rid-ob="figobch30kalldepthF6">Figure 6</a></h4><p class="float-caption no_bottom_margin">(a) Binocular rivalry can be demonstrated by placing a pen between
|
||
yourself and the screen. Keep your eye on the tip of the pen, and notice the
|
||
two bars merge. You may need to slowly move the pen from the screen toward
|
||
you. (b) Result of (a). </p></div></div><p><b>Panum's fusional area</b> is the region of binocular single vision. Outside
|
||
Panum's fusional area, physiological diplopia occurs. Using the haplopic method of
|
||
determining the horopter, Panum's area can be determined (<a class="figpopup" href="/books/NBK11512/figure/ch30kalldepth.F7/?report=objectonly" target="object" rid-figpopup="figch30kalldepthF7" rid-ob="figobch30kalldepthF7">Fig. 7</a>).</p><div class="iconblock whole_rhythm clearfix ten_col fig" id="figch30kalldepthF7" co-legend-rid="figlgndch30kalldepthF7"><a href="/books/NBK11512/figure/ch30kalldepth.F7/?report=objectonly" target="object" title="Figure 7" class="img_link icnblk_img figpopup" rid-figpopup="figch30kalldepthF7" rid-ob="figobch30kalldepthF7"><img class="small-thumb" src="/books/NBK11512/bin/kalldepthf7.gif" src-large="/books/NBK11512/bin/kalldepthf7.jpg" alt="Figure 7. Haplopic method of determining the horopter involves locating the region of single binocular vision at a distance of 40 cm." /></a><div class="icnblk_cntnt" id="figlgndch30kalldepthF7"><h4 id="ch30kalldepth.F7"><a href="/books/NBK11512/figure/ch30kalldepth.F7/?report=objectonly" target="object" rid-ob="figobch30kalldepthF7">Figure 7</a></h4><p class="float-caption no_bottom_margin">Haplopic method of determining the horopter involves locating the
|
||
region of single binocular vision at a distance of 40 cm. Panum's fusional
|
||
area lies between the outer and inner limits of the region of single
|
||
binocular vision. </p></div></div><div id="ch30kalldepth.Retinal_Disparity"><h3>Retinal Disparity</h3><p>Retinal disparate points are retinal points that give rise to different principal
|
||
visual direction and diplopia. However, retinal disparity within Panum's
|
||
fusional area (zone of single binocular vision) can be fused, resulting in
|
||
single vision. Retinal disparity is essential for stereoscopic depth perception
|
||
because stereoscopic depth perception results from fusion of slightly dissimilar
|
||
images. Because of the lateral displacement of our eyes, slightly dissimilar
|
||
retinal images result from the different perception of the same object from each
|
||
eye.</p></div></div><div id="ch30kalldepth.Clinical_Tests_Used_"><h2 id="_ch30kalldepth_Clinical_Tests_Used__">Clinical Tests Used to Measure Stereopsis</h2><p>There are two groups of clinical tests used to measure stereopsis. These are the
|
||
contour stereotests and the random-dot stereotest. Random-dot stereograms were first
|
||
used by Julesz (<a class="bk_pop" href="#ch30kalldepth.EXTYLES.1">1</a>) to
|
||
eliminate monocular cues. As there are no contours, depth perception (stereopsis)
|
||
can only be appreciated when binocular fusion occurs. Two process of stereopsis are
|
||
used, and these are local and global stereopsis. Local stereopsis exists to evaluate
|
||
the two horizontally disparate stimuli. This process is sufficient for contour
|
||
stereotests. Global stereopsis is required in random-dot stereogram when the
|
||
evaluation and correlation of corresponding points and disparate points are needed
|
||
over a large retinal area.</p><p>An example of a contour stereotest used in the clinic is the Titmus Fly Stereotest.
|
||
In the Titmus Fly Stereotest, horizontal disparity is presented via the vectographic
|
||
technique (<a class="bk_pop" href="#ch30kalldepth.EXTYLES.2">2</a>). When
|
||
tested at 40 cm, the fly has a disparity of 3,600 sec of arc; the disparities of the
|
||
animals range from 400 to 100 sec of arc, and the disparities of the Wirt rings
|
||
range from 800 to 40 sec of arc (<a class="figpopup" href="/books/NBK11512/figure/ch30kalldepth.F8/?report=objectonly" target="object" rid-figpopup="figch30kalldepthF8" rid-ob="figobch30kalldepthF8">Fig. 8</a>).</p><div class="iconblock whole_rhythm clearfix ten_col fig" id="figch30kalldepthF8" co-legend-rid="figlgndch30kalldepthF8"><a href="/books/NBK11512/figure/ch30kalldepth.F8/?report=objectonly" target="object" title="Figure 8" class="img_link icnblk_img figpopup" rid-figpopup="figch30kalldepthF8" rid-ob="figobch30kalldepthF8"><img class="small-thumb" src="/books/NBK11512/bin/kalldepthf8.gif" src-large="/books/NBK11512/bin/kalldepthf8.jpg" alt="Figure 8. Titmus Fly Stereotest." /></a><div class="icnblk_cntnt" id="figlgndch30kalldepthF8"><h4 id="ch30kalldepth.F8"><a href="/books/NBK11512/figure/ch30kalldepth.F8/?report=objectonly" target="object" rid-ob="figobch30kalldepthF8">Figure 8</a></h4><p class="float-caption no_bottom_margin">Titmus Fly Stereotest. </p></div></div><p>Examples of random-dot stereotests used in the clinic are the Frisby Stereotest, the
|
||
Randot Stereotest, the Random-dot E Stereotest, and the Lang Stereotest. The Frisby
|
||
Stereotest (<a class="figpopup" href="/books/NBK11512/figure/ch30kalldepth.F9/?report=objectonly" target="object" rid-figpopup="figch30kalldepthF9" rid-ob="figobch30kalldepthF9">Fig. 9</a>) uses real depth to determine
|
||
stereoacuity. Three perspex of different thicknesses are used. Four squares of
|
||
geometric shapes are painted on one side of the perspex. In one of the squares, a
|
||
circle of these geometric shapes is painted on the other side of the perspex. Both
|
||
the Randot (<a class="figpopup" href="/books/NBK11512/figure/ch30kalldepth.F10/?report=objectonly" target="object" rid-figpopup="figch30kalldepthF10" rid-ob="figobch30kalldepthF10">Fig. 10</a>) and the Random-dot E uses
|
||
crossed polarized filters. Disparity is also constructed vectographically. The
|
||
Randot Stereotest uses modified animals and ring designs with random dot backgrounds
|
||
to eliminate monocular cues. The Lang Stereotest uses a panographic technique (<a class="bk_pop" href="#ch30kalldepth.EXTYLES.2">2</a>) to present disparity;
|
||
therefore, no filters are required. Patients are required to identify pictures on
|
||
the Lang Stereotest. The Lang II Stereotest has a monocularly visible shape on it
|
||
(<a class="figpopup" href="/books/NBK11512/figure/ch30kalldepth.F11/?report=objectonly" target="object" rid-figpopup="figch30kalldepthF11" rid-ob="figobch30kalldepthF11">Fig. 11</a>).</p><div class="iconblock whole_rhythm clearfix ten_col fig" id="figch30kalldepthF9" co-legend-rid="figlgndch30kalldepthF9"><a href="/books/NBK11512/figure/ch30kalldepth.F9/?report=objectonly" target="object" title="Figure 9" class="img_link icnblk_img figpopup" rid-figpopup="figch30kalldepthF9" rid-ob="figobch30kalldepthF9"><img class="small-thumb" src="/books/NBK11512/bin/kalldepthf9.gif" src-large="/books/NBK11512/bin/kalldepthf9.jpg" alt="Figure 9. The Frisby Stereotest." /></a><div class="icnblk_cntnt" id="figlgndch30kalldepthF9"><h4 id="ch30kalldepth.F9"><a href="/books/NBK11512/figure/ch30kalldepth.F9/?report=objectonly" target="object" rid-ob="figobch30kalldepthF9">Figure 9</a></h4><p class="float-caption no_bottom_margin">The Frisby Stereotest. </p></div></div><div class="iconblock whole_rhythm clearfix ten_col fig" id="figch30kalldepthF10" co-legend-rid="figlgndch30kalldepthF10"><a href="/books/NBK11512/figure/ch30kalldepth.F10/?report=objectonly" target="object" title="Figure 10" class="img_link icnblk_img figpopup" rid-figpopup="figch30kalldepthF10" rid-ob="figobch30kalldepthF10"><img class="small-thumb" src="/books/NBK11512/bin/kalldepthf10.gif" src-large="/books/NBK11512/bin/kalldepthf10.jpg" alt="Figure 10. The Randot Stereotest." /></a><div class="icnblk_cntnt" id="figlgndch30kalldepthF10"><h4 id="ch30kalldepth.F10"><a href="/books/NBK11512/figure/ch30kalldepth.F10/?report=objectonly" target="object" rid-ob="figobch30kalldepthF10">Figure 10</a></h4><p class="float-caption no_bottom_margin">The Randot Stereotest. </p></div></div><div class="iconblock whole_rhythm clearfix ten_col fig" id="figch30kalldepthF11" co-legend-rid="figlgndch30kalldepthF11"><a href="/books/NBK11512/figure/ch30kalldepth.F11/?report=objectonly" target="object" title="Figure 11" class="img_link icnblk_img figpopup" rid-figpopup="figch30kalldepthF11" rid-ob="figobch30kalldepthF11"><img class="small-thumb" src="/books/NBK11512/bin/kalldepthf11.gif" src-large="/books/NBK11512/bin/kalldepthf11.jpg" alt="Figure 11. The Lang II." /></a><div class="icnblk_cntnt" id="figlgndch30kalldepthF11"><h4 id="ch30kalldepth.F11"><a href="/books/NBK11512/figure/ch30kalldepth.F11/?report=objectonly" target="object" rid-ob="figobch30kalldepthF11">Figure 11</a></h4><p class="float-caption no_bottom_margin">The Lang II. </p></div></div><p>All of the tests provide a measure of stereoacuity by asking the patient to identify
|
||
the correct target that has stereoscoptic depth (target with disparity). The working
|
||
distance and interpupillary distance will need to be taken into consideration when
|
||
calculating stereoacuity. Patients with disturbed binocular vision or different
|
||
refractive error in one eye will perform poorly on depth discrimination tests.</p></div><div id="ch30kalldepth.Acknowledgments"><h2 id="_ch30kalldepth_Acknowledgments_">Acknowledgments</h2><p>We thank Tim Fricke for providing Figs. 8-11. Further readings on this topic can be
|
||
found in Ogle (<a class="bk_pop" href="#ch30kalldepth.EXTYLES.3">3</a>), Moses
|
||
and Hart (<a class="bk_pop" href="#ch30kalldepth.EXTYLES.4">4</a>), and
|
||
Schwartz (<a class="bk_pop" href="#ch30kalldepth.EXTYLES.5">5</a>).</p></div><div id="ch30kalldepth.AFN1"><h2 id="_ch30kalldepth_AFN1_">About the Authors</h2><p>
|
||
<div class="graphic"><img src="/books/NBK11512/bin/psych1fu1.jpg" alt="Image psych1fu1.jpg" /></div>
|
||
Michael Kalloniatis was born in Athens Greece in 1958. He
|
||
received his optometry degree and Master's degree from the University of
|
||
Melbourne. His PhD was awarded from the University of Houston, College of
|
||
Optometry, for studies investigating colour vision processing in the monkey
|
||
visual system. Post-doctoral training continued at the University of Texas
|
||
in Houston with Dr Robert Marc. It was during this period that he developed
|
||
a keen interest in retinal neurochemistry, but he also maintains an active
|
||
research laboratory in visual psychophysics focussing on colour vision and
|
||
visual adaptation. He was a faculty member of the Department of Optometry
|
||
and Vision Sciences at the University of Melbourne until his recent move to
|
||
New Zealand. Dr. Kalloniatis is now the Robert G. Leitl Professor of
|
||
Optometry, Department of Optometry and Vision Science, University of
|
||
Auckland. e-mail: <a href="mailto:dev@null" data-email="ua.ude.wsnu@sitainollak.m" class="oemail">ua.ude.wsnu@sitainollak.m</a></p><p>
|
||
<div class="graphic"><img src="/books/NBK11512/bin/psych1fu2.jpg" alt="Image psych1fu2.jpg" /></div>
|
||
Charles Luu was born in Can Tho, Vietnam in 1974. He was
|
||
educated in Melbourne and received his optometry degree from the University
|
||
of Melbourne in 1996 and proceeded to undertake a clinical residency within
|
||
the Victorian College of Optometry. During this period, he completed
|
||
post-graduate training and was awarded the post-graduate diploma in clinical
|
||
optometry. His areas of expertise include low vision and contact lenses.
|
||
During his tenure as a staff optometrist, he undertook teaching of optometry
|
||
students as well as putting together the "Cyclopean Eye", in collaboration
|
||
with Dr Michael Kalloniatis. The Cyclopean Eye is a Web based interactive
|
||
unit used in undergraduate teaching of vision science to optometry students.
|
||
He is currently in private optometric practice as well as a visiting
|
||
clinician within the Department of Optometry and Vision Science, University
|
||
of Melbourne.</p></div><div id="ch30kalldepth.References"><h2 id="_ch30kalldepth_References_">References</h2><dl class="temp-labeled-list"><dt>1.</dt><dd><div class="bk_ref" id="ch30kalldepth.EXTYLES.1">Julesz B. Binocular depth perception of computer generated
|
||
patterns. <span><span class="ref-journal">Bell Syst Tech J. </span>1960;<span class="ref-vol">39</span>:1125–1162.</span></div></dd><dt>2.</dt><dd><div class="bk_ref" id="ch30kalldepth.EXTYLES.2">Fricke TR, Siderov J. Stereopsis, stereotest and their relation to vision screening and
|
||
clinical practice. <span><span class="ref-journal">Clin Exp Optom. </span>1997;<span class="ref-vol">80</span>:165–172.</span></div></dd><dt>3.</dt><dd><div class="bk_ref" id="ch30kalldepth.EXTYLES.3">Ogle KN. <span class="ref-journal">Researches in binocular vision.</span> London: Saunders; 1950. </div></dd><dt>4.</dt><dd><div class="bk_ref" id="ch30kalldepth.EXTYLES.4">Moses RA, Hart WM. <span class="ref-journal">Adler's physiology of the eye. Clinical application.</span> 8th
|
||
ed. St. Louis
|
||
(MO): The C. V. Mosby Company; 1987. </div></dd><dt>5.</dt><dd><div class="bk_ref" id="ch30kalldepth.EXTYLES.5">Schwartz SH. <span class="ref-journal">Visual perception.</span> 2nd
|
||
ed. (CT): Appleton and Lange; 1999. </div></dd></dl></div><div id="bk_toc_contnr"></div></div></div>
|
||
<div class="post-content"><div><div class="half_rhythm"><a href="/books/about/copyright/">Copyright</a>: © 2025 Webvision .<p class="small">All copyright for chapters belongs to the individual authors who created them. However, for non-commercial, academic purposes, images and content from the chapters portion of Webvision may be used with a non-exclusive rights under a Attribution, <a href="https://creativecommons.org/licenses/by-nc/4.0/" ref="pagearea=meta&targetsite=external&targetcat=link&targettype=uri">Noncommercial 4.0 International (CC BY-NC) Creative Commons license</a>. Cite Webvision, http://webvision.med.utah.edu/ as the source. Commercial applications need to obtain license permission from the administrator of Webvision and are generally declined unless the copyright owner can/wants to donate or license material. Use online should be accompanied by a link back to the original source of the material. All imagery or content associated with blog posts belong to the authors of said posts, except where otherwise noted.</p></div><div class="small"><span class="label">Bookshelf ID: NBK11512</span><span class="label">PMID: <a href="https://pubmed.ncbi.nlm.nih.gov/21413376" title="PubMed record of this page" ref="pagearea=meta&targetsite=entrez&targetcat=link&targettype=pubmed">21413376</a></span></div><div style="margin-top:2em" class="bk_noprnt"><a class="bk_cntns" href="/books/n/webvision/">Contents</a><div class="pagination bk_noprnt"><a class="active page_link prev" href="/books/n/webvision/ch29space_perceptio/" title="Previous page in this title">< Prev</a><a class="active page_link next" href="/books/n/webvision/brainvisual/" title="Next page in this title">Next ></a></div></div></div></div>
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<div xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"></div><div class="portlet"><div class="portlet_head"><div class="portlet_title"><h3><span>Views</span></h3></div><a name="Shutter" sid="1" href="#" class="portlet_shutter" title="Show/hide content" remembercollapsed="true" pgsec_name="PDF_download" id="Shutter"></a></div><div class="portlet_content"><ul xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="simple-list"><li><a href="/books/NBK11512/?report=reader">PubReader</a></li><li><a href="/books/NBK11512/?report=printable">Print View</a></li><li><a data-jig="ncbidialog" href="#_ncbi_dlg_citbx_NBK11512" data-jigconfig="width:400,modal:true">Cite this Page</a><div id="_ncbi_dlg_citbx_NBK11512" style="display:none" title="Cite this Page"><div class="bk_tt">Kalloniatis M, Luu C. The Perception of Depth. 2005 May 1 [Updated 2007 Jun 6]. In: Kolb H, Fernandez E, Jones B, et al., editors. Webvision: The Organization of the Retina and Visual System [Internet]. Salt Lake City (UT): University of Utah Health Sciences Center; 1995-. <span class="bk_cite_avail"></span></div></div></li><li><a href="/books/NBK11512/pdf/Bookshelf_NBK11512.pdf">PDF version of this page</a> (1.0M)</li><li><a href="/books/n/webvision/pdf/">PDF version of this title</a> (235M)</li></ul></div></div><div class="portlet"><div class="portlet_head"><div class="portlet_title"><h3><span>In this Page</span></h3></div><a name="Shutter" sid="1" href="#" class="portlet_shutter" title="Show/hide content" remembercollapsed="true" pgsec_name="page-toc" id="Shutter"></a></div><div class="portlet_content"><ul xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="simple-list"><li><a href="#ch30kalldepth.Stereopsis" ref="log$=inpage&link_id=inpage">Stereopsis</a></li><li><a href="#ch30kalldepth.Monocular_Cues" ref="log$=inpage&link_id=inpage">Monocular Cues</a></li><li><a href="#ch30kalldepth.Binocular_Cues" ref="log$=inpage&link_id=inpage">Binocular Cues</a></li><li><a href="#ch30kalldepth.Clinical_Tests_Used_" ref="log$=inpage&link_id=inpage">Clinical Tests Used to Measure Stereopsis</a></li><li><a href="#ch30kalldepth.Acknowledgments" ref="log$=inpage&link_id=inpage">Acknowledgments</a></li><li><a href="#ch30kalldepth.AFN1" ref="log$=inpage&link_id=inpage">About the Authors</a></li><li><a href="#ch30kalldepth.References" ref="log$=inpage&link_id=inpage">References</a></li></ul></div></div><div class="portlet"><div class="portlet_head"><div class="portlet_title"><h3><span>Related Items in Bookshelf</span></h3></div><a name="Shutter" sid="1" href="#" class="portlet_shutter" title="Show/hide content" remembercollapsed="true" pgsec_name="source-links" id="Shutter"></a></div><div class="portlet_content"><ul xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="simple-list"><li><a href="https://www.ncbi.nlm.nih.gov/books?term=%22reference%20works%22%5BResource%20Type%5D" ref="pagearea=source-links&targetsite=external&targetcat=link&targettype=uri">All Reference Works</a></li><li><a href="https://www.ncbi.nlm.nih.gov/books?term="textbooks"%5BResource%20Type%5D" ref="pagearea=source-links&targetsite=external&targetcat=link&targettype=uri">All Textbooks</a></li></ul></div></div><div class="portlet"><div class="portlet_head"><div class="portlet_title"><h3><span>Similar articles in PubMed</span></h3></div><a name="Shutter" sid="1" href="#" class="portlet_shutter" title="Show/hide content" remembercollapsed="true" pgsec_name="PBooksDiscovery_RA" id="Shutter"></a></div><div class="portlet_content"><ul><li class="brieflinkpopper two_line"><a class="brieflinkpopperctrl" href="/pubmed/29630208" ref="ordinalpos=1&linkpos=1&log$=relatedarticles&logdbfrom=pubmed">Agnosia.</a><span class="source">[StatPearls. 2025]</span><div class="brieflinkpop offscreen_noflow">Agnosia.<div class="brieflinkpopdesc"><em xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="author">Kumar A, Wroten M. </em><em xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="cit">StatPearls. 2025 Jan</em></div></div></li><li class="brieflinkpopper two_line"><a class="brieflinkpopperctrl" href="/pubmed/30020595" ref="ordinalpos=1&linkpos=2&log$=relatedarticles&logdbfrom=pubmed">Peer Play.</a><span class="source">[StatPearls. 2025]</span><div class="brieflinkpop offscreen_noflow">Peer Play.<div class="brieflinkpopdesc"><em xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="author">Scott HK, Cogburn M. </em><em xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="cit">StatPearls. 2025 Jan</em></div></div></li><li class="brieflinkpopper two_line"><a class="brieflinkpopperctrl" href="/pubmed/39588128" ref="ordinalpos=1&linkpos=3&log$=relatedarticles&logdbfrom=pubmed">Progressive changes in binocular perception from stereopsis to rivalry.</a><span class="source">[Front Psychol. 2024]</span><div class="brieflinkpop offscreen_noflow">Progressive changes in binocular perception from stereopsis to rivalry.<div class="brieflinkpopdesc"><em xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="author">Hasegawa Y, Kondo HM. </em><em xmlns:np="http://ncbi.gov/portal/XSLT/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" class="cit">Front Psychol. 2024; 15:1472278. 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