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1. slight corneal opacity.
2. an oily preparation for use in a nebulizer.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

neb·u·la (nebul.),

, pl.


(neb'yū-lă, -lē),
1. A translucent foglike opacity of the cornea.
2. A class of oily preparations, intended for application by atomization.
3. A spray.
[L. fog, cloud, mist]
Farlex Partner Medical Dictionary © Farlex 2012


n. pl. nebu·lae (-lē′) or nebu·las
1. Astronomy
a. A diffuse cloud of interstellar dust or gas or both, visible as luminous patches or areas of darkness depending on the way the mass absorbs or reflects incident light or emits its own light.
b. A galaxy. No longer in technical use.
2. Medicine
a. A cloudy spot on the cornea.
b. A liquid preparation for use in a nebulizer.

neb′u·lar adj.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


, pl. nebulae (neb'yū-lă, -lē)
1. A translucent foglike opacity of the cornea.
2. A spray.
[L. fog, cloud, mist]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


A cloudy spot on the CORNEA of the eye. A central nebula can severely interfere with clear vision.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005


Dense, white, corneal opacity caused by scar tissue. A localized leukoma appears as a whitish scar surrounded by normal cornea. A generalized leukoma involves the entire cornea, which appears white, often with blood vessels coursing over its surface. Visual impairment depends on the location and extent of the leukoma. If the opacity is faint, it is called a nebula. Note: also spelt leucoma. See hyperacuity; corneal ulcer.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
References in periodicals archive ?
After half time, Nebulas capitalised on their depleted opponents to outscore them 30-11.
In this nebula, the Sword of Orion, only the blue parts are visible.
Combined with the recent acquisition of Scandinavia's Coresec Systems, SecureLink and Nebulas will operate across six countries in Europe and employ more than 550 members of staff.
Mohammed Al-Shroogi, Co-CEO at Investcorp, said, "As a combined group SecureLink, Coresec and Nebulas will form the second largest cybersecurity player in Europe providing best in breed products suited to a wide range of industries.
The new observations, which home in on nebulas from two satellite galaxies of the Milky Way, may also provide insight into the strong visible-light emissions that have been observed coming from some distant galaxies.
To celebrate their deaths, Nasa published obituaries for the three planetary nebulas:
A planetary nebula arises when an old, sunlike star contracts under its own gravity to become a compact object called a white dwarf.
There he completed his father's work by mapping the distribution of stars and nebula over the Southern Hemisphere.
Trauger of NASA's Jet Propulsion Laboratory in Pasadena, Calif., used the Hubble Space Telescope to examine several compact, relatively bright, and presumably young planetary nebulas. The researchers sought out youthful nebulas in hopes that these clouds would retain clues to their formation.
Turning the Hubble Space Telescope toward the Orion Nebula, astronomers have discovered and photographed 15 infant stars surrounded by dense, flattened disks of dust.
As reported in the June 20 ASTROPHYSICAL JOURNAL, Jacoby and his collaborators measured the light emitted by 486 candidate planetary nebulas in six galaxies belonging to the Virgo cluster.