WordNet

inability to see clearly in dim light; due to a deficiency of vitamin A or to a retinal disorder (同)night_blindness, moon_blindness
inability to see clearly in bright light (同)day blindness
the time after sunset and before sunrise while it is dark outside (同)nighttime, dark
a period of ignorance or backwardness or gloom
a shortening of nightfall; "they worked from morning to night"
darkness; "it vanished into the night"
the dark part of the diurnal cycle considered a time unit; "three nights later he collapsed"
the period spent sleeping; "I had a restless night"
the time between sunset and midnight; "he watched television every night"
the state of being blind or lacking sight (同)sightlessness, cecity

PrepTutorEJDIC

〈C〉〈U〉『夜』,晩,夜間 / 〈U〉(夜の)暗やみ,夜蔭 / 〈U〉《文》(精神的に)まっ暗な状態(時),やみ / 〈C〉(特定の行事・目的に当てられる)晩,夜 / 『夜の』,夜間[用]の;夜勤の;夜行[性]の
盲目 / 無知,盲信
近くの(near) / 近くに(で) / ほとんど / …の近く(そば)に
夜な夜な,毎晩

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/05/11 23:02:35」(JST)

wiki en

Nyctalopia (from Greek νύκτ-, nykt- "night"; αλαός, alaos "blind, not seeing", and ὄψ, ops "eye") also called "Night Blindness" is a condition making it difficult or impossible to see in relatively low light. It is a symptom of several eye diseases. Night blindness may exist from birth, or be caused by injury or malnutrition (for example, a lack of vitamin A). It can be described as insufficient adaptation to darkness.

The most common cause of nyctalopia is retinitis pigmentosa, a disorder in which the rod cells in the retina gradually lose their ability to respond to the light. Patients suffering from this genetic condition have progressive nyctalopia and eventually their daytime vision may also be affected. In X-linked congenital stationary night blindness, from birth the rods either do not work at all, or work very little, but the condition doesn't get worse. Another cause of night blindness is a deficiency of retinol, or vitamin A, found in fish oils, liver and dairy products.

The opposite problem, the inability to see in bright light, is known as hemeralopia and is much rarer.

Since the outer area of the retina is made up of more rods than cones, loss of peripheral vision often results in night blindness. Individuals suffering from night blindness not only see poorly at night, but also require some time for their eyes to adjust from brightly lit areas to dim ones. Contrast vision may also be greatly reduced. Rods contain a pigment called rhodopsin. When light falls on rhodopsin, it undergoes a series of conformational changes ultimately generating electrical signals which are carried to the brain via the optic nerve. In the absence of light, rhodopsin is regenerated. The body synthesizes rhodopsin from vitamin A, which is why a deficiency in vitamin A causes poor night vision.

Refractive "vision correction" surgery is a widespread cause of nyctalopia due to the impairment of contrast sensitivity function (CSF) which is induced by intraocular light-scatter resulting from surgical intervention in the natural structural integrity of the cornea.^[1]

Causes

congenital night blindness (Retinitis pigmentosa)
Certain medications, such as phenothiazines^[2]
Oguchi disease
pathological myopia
peripheral cortical cataract
refractive surgery (LASIK, photorefractive keratectomy, radial keratotomy)
retinitis pigmentosa
Sorsby's fundus dystrophy
Vitamin A deficiency

Historical usage

Aulus Cornelius Celsus, writing ca. 30 AD, described night blindness and recommended an effective dietary supplement: "There is besides a weakness of the eyes, owing to which people see well enough indeed in the daytime but not at all at night; in women whose menstruation is regular this does not happen. But success sufferers should anoint their eyeballs with the stuff dripping from a liver whilst roasting, preferably of a he-goat, or failing that of a she-goat; and as well they should eat some of the liver itself."

Historically, nyctalopia, also known as moonblink, was a temporary night blindness believed to be caused by sleeping in moonlight in the tropics.^[3]

Nyctalopia with animals

Congenital stationary night blindness is also an ophthalmologic disorder in horses with leopard spotting patterns, such as the Appaloosa. It is present at birth (congenital), not sex-linked, non-progressive and affects the animal's vision in conditions of low lighting.^[4] CSNB is usually diagnosed based on the owner's observations, but some horses have visibly abnormal eyes: poorly-aligned eyes (dorsomedial strabismus) or involuntary eye movement (nystagmus).^[4] In horses, CSNB has been linked with the leopard complex color pattern since the 1970s.^[5] A 2008 study theorizes that both CSNB and leopard complex spotting patterns are linked to the TRPM1 gene.^[6] The region on horse chromosome 1 to which the Lp gene has now been localized also encodes a protein that channels calcium ions, a key factor in the transmission of nerve impulses. This protein, found in the retina and the skin, exists in fractional percentages of the normal levels found in homozygous Lp/Lp horses and so compromises the basic chemical reaction for nerve impulse transmission.^[4]

References

^ Laser in situ keratomileusis for myopia and the contrast sensitivity function Nadia-Marie Quesnel, John V Lovasik, Christian Ferremi, Martin Boileau, Catherine Ieraci Journal of Cataract & Refractive Surgery June 2004 (Vol. 30, Issue 6, Pages 1209–1218)
^ Goldman, Lee. Goldman's Cecil Medicine (24th ed. ed.). Philadelphia: Elsevier Saunders. p. 2429. ISBN 1437727883.
^ The Sailor's Word-Book, Admiral W.H. Smyth, p. 483; Conway Maritime Press, UK, 1991. ISBN 0-85177-972-7
^ ^a ^b ^c Bellone, Rebecca R; Brooks SA, Sandmeyer L, Murphy BA, Forsyth G, Archer S, Bailey E, Grahn B (August 2008). "Differential Gene Expression of TRPM1, the Potential Cause of Congenital Stationary Night Blindness and Coat Spotting Patterns (LP) in the Appaloosa Horse (Equus caballus)". Genetics (Genetics Society of America) 179 (4): 1861–1870. doi:10.1534/genetics.108.088807. PMC 2516064. PMID 18660533. Cite uses deprecated parameters (help)
^ Witzel CA, Joyce JR, Smith EL. Electroretinography of congenital night blindness in an Appaloosa filly. Journal of Equine Medicine and Surgery 1977; 1: 226–229.
^ Oke, Stacey, DVM, MSc (August 31, 2008). "Shedding Light on Night Blindness in Appaloosas" (Registration required). The Horse. Retrieved 2009-02-07.

UpToDate Contents

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1. ビタミンAの概要 overview of vitamin a
2. 網膜色素変性症：臨床症状および診断 retinitis pigmentosa clinical presentation and diagnosis
3. シェーグレン・ラルソン症候群 sjogren larsson syndrome
4. 持続的なアルコール依存症患者における栄養状態 nutritional status in patients with sustained heavy alcohol use
5. 腫瘍随伴性視覚症候群 paraneoplastic visual syndromes

English Journal

Spectrum of Cav1.4 dysfunction in congenital stationary night blindness type 2.

Burtscher V1, Schicker K1, Novikova E2, Pöhn B1, Stockner T3, Kugler C1, Singh A4, Zeitz C5, Lancelot ME5, Audo I6, Leroy BP7, Freissmuth M3, Herzig S2, Matthes J2, Koschak A8.
Biochimica et biophysica acta.Biochim Biophys Acta.2014 Aug;1838(8):2053-65. doi: 10.1016/j.bbamem.2014.04.023. Epub 2014 May 4.
Defective retinal synaptic transmission in patients affected with congenital stationary night blindness type 2 (CSNB2) can result from different dysfunction phenotypes in Cav1.4 L-type calcium channels. Here we investigated two prototypical Cav1.4 variants from either end of the functional spectrum.
PMID 24796500

Phase I dose-escalation study of the HSP90 inhibitor AUY922 in Japanese patients with advanced solid tumors.

Doi T1, Onozawa Y, Fuse N, Yoshino T, Yamazaki K, Watanabe J, Akimov M, Robson M, Boku N, Ohtsu A.
Cancer chemotherapy and pharmacology.Cancer Chemother Pharmacol.2014 Jul 25. [Epub ahead of print]
PURPOSE: AUY922 is a potent non-geldanamycin inhibitor of heat-shock protein 90. This study was carried out in Japanese patients to determine the maximum tolerated dose (MTD), and to characterize safety, tolerability and pharmacokinetics of single-agent AUY922.METHODS: Japanese patients with advance
PMID 25059319