nyctalopia


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nyctalopia

 [nik″tah-lo´pe-ah]
2. sometimes incorrectly used as a synonym for hemeralopia.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

nyc·ta·lo·pi·a

(nik-tă-lō'pē-ă),
Decreased ability to see in reduced illumination. Seen in patients with impaired rod function; often associated with a deficiency of vitamin A.
[nyct- + G. alaos, obscure, + ōps, eye]
Farlex Partner Medical Dictionary © Farlex 2012

nyctalopia

(nĭk′tə-lō′pē-ə)
nyc′ta·lo′pic (-lō′pĭk, -lŏp′ĭk) adj.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

nyc·ta·lo·pi·a

(nik'tă-lō'pē-ă)
Decreased ability to see in reduced illumination. Seen in patients with impaired rod function; often associated with a deficiency of vitamin A.
Synonym(s): night blindness.
[nyct- + G. alaos, obscure, + ōps, eye]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

nyctalopia

Inability to see well in conditions of poor illumination. NIGHT BLINDNESS. From the Greek nyktos, night, alaos, blind and ops, the eye.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

hemeralopia

Term used to mean either night blindness in which there is a partial or total inability to see in the dark associated with a loss of rod function or vitamin A deficiency; or day blindness in which there is reduced vision in daylight while vision is normal in the dark. Syn. nyctalopia (this term is only synonymous with night blindness); night sight (this term is only synonymous with day blindness). See girate atrophy; congenital stationary night blindness; choroideremia; Oguchi's disease; retinitis pigmentosa.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
References in periodicals archive ?
Most of the dogs were presented with initial signs of nyctalopia, followed by progressive hemerlopia until the affected animal was totally blind.
All 31 affected dogs described in present report showed no obvious visual impairment except nyctalopia at initial stage which gradually progress to day blindness in few months to years resulting in complete blindness.
Vitamin A deficiency is a global issue and can result a number of health issues, including reversible night blindness, or nyctalopia. Young children and pregnant women are most at risk; according to the World Health Organization (WHO), as many as 250 million school age children may be affected.
Nyctalopia had begun in early childhood with onset ranging from 2 to 6 years of age.
Wagner syndrome may further be differentiated from Snowflake degeneration by its alternative genetic mutation (in CSPG2), more pronounced chorioretinal atrophy, nyctalopia, pseudoexotropia from the congenital temporal displacement of the fovea, and poorer end visual outcome.
A patient presents with a loss of peripheral vision and nyctalopia.
Despite performing better on the acuity chart, she had continuous episodes of poor night vision (nyctalopia), frosty blurring of vision (described as 'looking through glass' or 'through water') or a 'bush fire' effect and 'shimmering vision'; this is typically reported by patients as the 'ceiling fan effect' (when closing both eyes one is left with an image of multiple ceiling fans whirring around).
c) Nyctalopia is thought to more common than oscillopsia in BCR
Patients with RP may complain of difficulties with their vision in dimly lit surroundings or total nyctalopia. On examination, typical findings are a constricted visual field, retinal bone-spicule pigmentation, arteriolar attenuation and waxy optic disc pallor.