coma aberration

co·ma ab·er·ra·tion

1. the distortion of image formation created when a bundle of light rays enters an optical system not parallel to the optic axis.
2. in botany, any tuft, as the hairs on a seed, or the greenery on a radish or a pineapple.
Synonym(s): coma (3)
[G. komē, hair, foliage]

co·ma ab·er·ra·tion

(kō'mă ab-ĕr-ā'shŭn)
The distortion of image formation created when a bundle of light rays enters an optic system not parallel to the optic axis.
Synonym(s): coma (3) .
[G. komē, hair, foliage]
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References in periodicals archive ?
Coma aberration results from the decentration of the optic system, clinically known as the kappa angle, and this natural condition manifests itself as a decentralized spherical aberration.
Coma aberration increased to 0.117 [+ or -] 0.145([micro]m) at month 3 and to 0.106 [+ or -] 0.129 ([micro]m) at month 6 and showed statistically significant increases after orthokeratology (F =3.536, P = 0.044).
Mean coma aberration was 0.25[+ or -]0.01 [micro]m preoperatively and 0.66[+ or -]0.3 [micro]m at 12 months postoperatively (p<0.001), while trefoil aberration was 0.20[+ or -]0.1 [micro]m preoperatively and 0.22[+ or -]0.1 [micro]m at 12 months postoperatively (p<0.04) (Table 4).
Early markers include: supranuclear cortical cataract, coma aberration, retinal nerve fibre layer thinning and drusen, especially when present in younger patients--perhaps something we should look more carefully for in our 50+ year old patients?
This study only analyzed the changes of total higher-order aberrations, total coma aberration, total spherical aberration, and total trefoil aberration corresponding to the RMS value in the children with with-the-rule astigmatism.
Pre- and postoperative examination included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), corneal topography simulated K average readings (K ave.), apical curvature (AK), and surface aberrometry (coma aberration) by CSO EyeTop Topographer (Costruzione Strumenti Oftalmici, Florence, Italy).
Suzaki, "The effects of entrance pupil centration and coma aberrations on myopic progression following orthokeratology," Clinical and Experimental Optometry, vol.
Suzaki, "The effects ofentrance pupil centration and coma aberrations on myopic progression following orthokeratology," Clinical and Experimental Optometry, vol.
.The lens has minimised axial and lateral chromatic aberrations, coma aberrations and geometric distortion.
Caption: Figure 3: Illustration of the coma aberrations and measurements of tilt and decentration in a Scheimpflug image of a typical patient from the open-globe-injury group.
Preoperatively, the mean total corneal HOAs were 0.26 [+ or -] 0.14 [micro]m (range 0.23-0.47 [micro]m), the mean coma aberrations 0.28 [+ or -] 0.17 [micro]m (range 0.24-0.31 [micro]m), and the mean spherical aberrations 0.26 [+ or -] 0.11 [micro]m (range 0.27-0.24 [micro]m).
Some studies suggest that coma aberrations were affected by decentration after SMILE [8].