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(physiology) the responsive adjustment of a sense organ (as the eye) to varying conditions (as of light)
a written work (as a novel) that has been recast in a new form; "the play is an adaptation of a short novel" (同)version
the process of adapting to something (such as environmental conditions) (同)adaption, adjustment

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〈U〉適応,順応 / 〈U〉脚色,翻案;〈C〉翻案物,改作物

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/05/01 11:12:15」(JST)

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The CIE 1951 scotopic luminosity function. The horizontal axis is wavelength in nm.

Simulated examples of vision under low light. Top: human; bottom: cat

Scotopic vision is the vision of the eye under low light conditions. The term comes from Greek skotos meaning darkness and -opia meaning a condition of sight.^[1] In the human eye cone cells are nonfunctional in low light – scotopic vision is produced exclusively through rod cells which are most sensitive to wavelengths of light around 498 nm (green-blue) and are insensitive to wavelengths longer than about 640 nm (red).

Scotopic vision is dominated by retina amacrine cells, specifically all-amacrine cells. AII-amacrine cells capture rod bipolar cell input and redistribute it to cone bipolar cells since rod-driven bipolar cells do not synapse on ganglion cells. ^[2]

Scotopic vision occurs at luminance levels of 10⁻³^[3] to 10⁻⁶^{[citation needed]} cd/m². Other species are not universally color blind in low-light conditions. The Elephant Hawk-moth (Deilephila elpenor) displays advanced color discrimination even in dim starlight.^[4]

Mesopic vision occurs in intermediate lighting conditions (luminance level 10⁻³ to 10^0.5 cd/m²) and is effectively a combination of scotopic and photopic vision. This however gives inaccurate visual acuity and color discrimination.

In normal light (luminance level 10 to 10⁸ cd/m²), the vision of cone cells dominates and is photopic vision. There is good visual acuity (VA) and color discrimination.

In scientific literature, one occasionally encounters the term scotopic lux which corresponds to photopic lux, but uses instead the scotopic visibility weighting function.^[5]

The normal human observer’s relative wavelength sensitivity will not change due to background illumination change under scotopic vision. The wavelength sensitivity is determined by the rhodopsin photopigment. This is a red pigment and can be seen at the back of eye of animals that have a white background to their eye called Tapetum lucidum. The pigment is not noticeable under photopic and mesopic conditions. The principle that the wavelength sensitivity does not change during scotopic vision led to the ability to detect two functional cone classes in individuals. If two cone classes are present, then their relative sensitivity will change the behavioral wavelength sensitivity. Therefore, experimentation can determine “the presence of two cone classes by measuring wavelength sensitivity on two different backgrounds and noting a change in the observer’s relative wavelength sensitivity.” For adaption to occur at very low levels, the human eye needs to have a large sample of light across the signal in order to get a reliable image. This leads to the human eye being unable to resolve high spatial frequencies in low light since the observer is spatially averaging the light signal.^[6]

The behavior of the rhodopsin photopigment explains why the human eye cannot resolve lights with different spectral power distributions under low light. The reaction of this single photopigment will give the same quanta for 400 nm light and 700 nm light. Therefore, this photopigment only maps the rate of absorption and does not encode information about the relative spectral composition of the light.^[7]

Another reason that vision is poor under scotopic vision is that rods, which are the only cells active under scotopic vision, converge to a smaller number of neurons in the retina. This many-to-one ratio leads to poor spatial frequency sensitivity.^[8]

References

^ scotopia at dictionary.com
^ Marc, R. E.; Anderson, J. R.; Jones, B. W.; Sigulinsky, C. L.; Lauritzen, J. S. (2014). "The AII amacrine cell connectome: A dense network hub". Frontiers in Neural Circuits. 8: 104. doi:10.3389/fncir.2014.00104. PMC 4154443. PMID 25237297.
^ http://faculty.washington.edu/sbuck/545ColorClass/PokornyCh2.1979b.PDF
^ Scotopic colour vision in nocturnal hawkmoths
^ Photobiology: The Science of Light and Life (2002), Lars Olof Björn, p.43, ISBN 1-4020-0842-2
^ Foundations of Vision (1995), Brian A. Wandell, Chapter 9 Color
^ Foundations of Vision (1995), Brian A. Wandell, Chapter 4 Wavelength Encoding
^ Foundations of Vision (1995), Brian A. Wandell, Chapter 3 The Photoreceptor Mosaic

Marc, R. E.; Anderson, J. R.; Jones, B. W.; Sigulinsky, C. L.; Lauritzen, J. S. (2014). "The AII amacrine cell connectome: A dense network hub". Frontiers in Neural Circuits. 8: 104. doi:10.3389/fncir.2014.00104. PMC 4154443. PMID 25237297.

UpToDate Contents

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English Journal

Evolutionary dynamics of Rh2 opsins in birds demonstrate an episode of accelerated evolution in the New World warblers (Setophaga).

Bloch NI1, Price TD, Chang BS.
Molecular ecology.Mol Ecol.2015 May;24(10):2449-62. doi: 10.1111/mec.13180. Epub 2015 Apr 20.
Low rates of sequence evolution associated with purifying selection can be interrupted by episodic changes in selective regimes. Visual pigments are a unique system in which we can investigate the functional consequences of genetic changes, therefore connecting genotype to phenotype in the context o
PMID 25827331

Multimodal characterization of proliferative diabetic retinopathy reveals alterations in outer retinal function and structure.

Boynton GE1, Stem MS1, Kwark L2, Jackson GR3, Farsiu S4, Gardner TW5.
Ophthalmology.Ophthalmology.2015 May;122(5):957-67. doi: 10.1016/j.ophtha.2014.12.001. Epub 2015 Jan 17.
PURPOSE: To identify changes in retinal function and structure in persons with proliferative diabetic retinopathy (PDR), including the effects of panretinal photocoagulation (PRP).DESIGN: Cross-sectional study.PARTICIPANTS: Thirty adults who underwent PRP for PDR, 15 adults with untreated PDR, and 1
PMID 25601533

The kinetics of regeneration of rhodopsin under enzyme-limited availability of 11-cis retinoid.

Lamb TD1, Corless RM2, Pananos AD3.
Vision research.Vision Res.2015 May;110(Pt A):23-33. doi: 10.1016/j.visres.2015.02.014. Epub 2015 Mar 10.
In order to describe the regeneration of rhodopsin and the recovery of visual sensitivity following exposure of the eye to intense bleaching illumination, two models have been proposed, in which there is either a "resistive" or an "enzymatic" limit to the supply of retinoid. A solution has previousl
PMID 25769401

Japanese Journal

薄明視は明所視とはどう連う?(<特集>薄明りにおける目の特性に基づく高効率で安全な照明)

阿山みよし
照明学会誌 97(4), 202-204, 2013-04-01
… Next, variation of dark adaptation curve is indicated. … Although dark adaptation curve is known to show double phases, single phase curve appears if the experimental condition is sensitive only to cones or rods. … Thus the shape of dark adaptation curve corresponds to the functional light level and retinal distribution of cones and rods. … Finally, the scotopic and photopic spectral sensitivity functions are compared. …
NAID 110009596821

ICR系マウスにおける自然発生性網膜機能異常のタイプ及びその発生頻度に関する検討

川崎一哉,宮本実,青木正美,杉本眞次,中下富雄,繁田真樹,今井良悦
比較眼科研究 27(0), 23-29, 2008
網膜毒性は失明の恐れから重大な毒性の一つと考えられており、網膜電図（ERG）検査は網膜毒性を検出するための有効な手段である。一方、ICR系マウスは薬物の前臨床安全性評価に汎用されるクローズドコロニーマウスである。実験に使用する実験動物の特性を把握することは、精度の高い安全性評価を行う上で重要であるが、ICR系マウスにおいて、どのような網膜機能異常がどの程度の頻度で存在するのか、その詳細は不明である …
NAID 130003378075

Negative scotopic ERG and photopic ERG ON response impairment in a patient with normal dark adaptation

Tanimoto Naoyuki,Usui Tomoaki,Ichibe Mineo,Kuze Manami,Takagi Mineo,Hasegawa Shigeru,Sato Masahisa,Tanaka Keiko,Abe Haruki,高木峰夫
Documenta ophthalmologica 113(3), 171-177, 2006
… Purpose: To present ocular findings in a patient who showed negative scotopic electroretinogram (ERG) and reduced ON response, but normal dark adaptation. … He had normal contrast sensitivity and normal dark adaptation. … The scotopic standard combined ERG response showed negative configuration. …
NAID 120005323833