Linked Life Data

8927317

Source:http://linkedlifedata.com/resource/pubmed/id/8927317

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-11-12
pubmed:abstractText
Foveation periods are brief intervals in the congenital nystagmus (CN) waveform when the image is on or near the fovea and eye velocity is relatively slow. The purpose of this study was to determine how visual acuity depends on image velocity for foveation periods of different durations. Visual acuity was measured using high-contrast, single Landolt Cs in four normal observers during image motion simulating that in jerk nystagmus. The "simulated foveation periods" ranged from 20 to 100 ms in duration and 0 to 16 degrees approximately in velocity. The "critical velocity" was defined as the velocity during simulated foveation periods that produced a just-noticeable worsening of acuity (0.05 and 0.1 logMAR) from that in the zero-velocity condition. Critical velocity increased from approximately 3 degrees approximately for simulated foveation durations between 100 and 40 ms to approximately 5 degrees approximately for a simulated foveation duration of 20 ms. Critical velocities increased further when the targets were presented peripherally or with optical blur, to introduce an additional acuity loss. A consequence of these findings is that less recovery of acuity should be expected when retinal image motion is reduced in individuals with CN if a sensory acuity deficit coexists.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1040-5488
pubmed:author
pubmed:issnType
Print
pubmed:volume
73
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
92-103
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Velocity criteria for "foveation periods" determined from image motions simulating congenital nystagmus.
pubmed:affiliation
College of Optometry, University of Houston, Texas, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't