Editing Visual field (section)

{{Short description|Area in visual space that can be seen when the eye fixates a point}}
The '''visual field''' is "that portion of space in which objects are visible at the same moment during steady fixation of the gaze in one direction";<ref name="Traquair">{{cite book |last = Traquair |first = Harry Moss |date= 1938 |title= An Introduction to Clinical Perimetry, Chpt. 1 |location= London|publisher= Henry Kimpton}}</ref> in ophthalmology and neurology the emphasis is mostly on the structure inside the visual field and it is then considered “the field of functional capacity obtained and recorded by means of perimetry”.<ref>{{cite book |last1=Aulhorn |first1=Elfriede |last2=Harms |first2=Heinrich | title= Visual Perimetry. In: Handbook of Sensory Physiology book series (1536, volume 7/4 | pages= 102–145 |year=1972 | doi= 10.1007/978-3-642-88658-4_5}}</ref><ref>A related definition is “The visual field refers to the area visible during stable fixation of the eyes, specified in degrees of visual angle.”</ref><ref name="Strasburger_Poeppel">Strasburger, Hans; Pöppel, Ernst (2002). Visual Field. In G. Adelman &amp; B.H. Smith (Eds): ''Encyclopedia of Neuroscience''; 3rd edition, on CD-ROM. Elsevier Science B.V., Amsterdam, New York. </ref>

However, the visual field can also be understood as a predominantly ''perceptual'' concept and its definition then becomes that of the "spatial array of visual sensations available to observation in [[introspection]]ist psychological experiments"<ref>{{cite journal |last=Smythies |first=J |s2cid=27088663 |title=A note on the concept of the visual field in neurology, psychology, and visual neuroscience |journal=Perception |volume=25 |issue=3 |pages=369–71 |year=1996 |pmid=8804101 |doi=10.1068/p250369 }}</ref>
(for example in van Doorn et al., 2013).<ref>{{cite journal |last1=van Doorn |first1=Andrea|last2=Koenderink |first2=Jan |last3=Wagemans |first3=Johan | title= Exocentric pointing in the visual field |journal=i-Perception |volume=4 |pages= 532–542 |year=2013 |issue=8 |pmid=8804101 |doi= 10.1068/i0609|pmc=4129387 }}</ref>

The corresponding concept for [[optical instrument]]s and [[image sensor]]s is the [[field of view]] (FOV). In humans and animals, the FOV refers to the area visible when eye movements – if possible for the species – are allowed.

In [[optometry]], [[ophthalmology]], and [[neurology]], a [[visual field test]] is used to determine whether the visual field is affected by diseases that cause local [[scotoma]] or a more extensive [[visual loss|loss of vision]] or a reduction in sensitivity (increase in threshold).