Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ADAPTATION, OCULAR”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 739 records · Page 41Linked to original sources
PubMed1992

[The relation between saccadic eye movements and electrooculogram during light and dark adaptations].

The relation between the amplitudes of saccadic eye movements and the resting potential changes detected around human eyeballs under light and dark adaptations was clarified by means of simultaneous measurements of electrooculogram (EOG) and eye movements. The authors previously reported that the potential changes are proportional to the horizontal saccadic eye movements within +/- 15 degrees (visual angle) under conditions of the room light of approximately 60 lux. There are few reliable data indicative of the presence of the above relations under light and dark adaptations. The result of the simultaneous measurements of EOG and eye movements during the light and dark adaptation at 2-minute intervals in 9 normal subjects showed that the resting potential changes were in direct proportion of the amplitudes of the saccadic eye movements at any time within +/- 20 degrees. In these experiments, the eye positions were monitored with the eye mark recorder during the eye movements. In case the eye positions excursioned from a target, the exact EOG was calculated by measuring eye positions and correcting the EOG errors.

Adaptation, Ocular↗
PubMed1990

[Modification of an automated perimeter for dark- and light-adapted perimetry].

A modified automated projection static perimeter which can measure thresholds with lights of three different wavelengths in light-adapted as well as in dark adapted state is described. With the modifications described, this instrument can evaluate relative states of rod and cone mechanisms respectively within the visual field range of 72 degrees. These modifications also enable dark-adapted two-color static perimetry quantitatively across the visual field including profile measurement. Results obtained from normal subjects with these techniques permit assessment of the sensitivity in dark and light and also determination of photoreceptor mediation in the dark. These techniques can evaluate rod and cone dysfunctions separately unlike other retinal function tests, and may show that different mechanisms even in one clinical entity of retinal dystrophies, as well as retinal degenerations, can be demonstrated.

Adaptation, Ocular↗
PubMed1988

Rod light and dark adaptation influence cone-mediated spatial acuity.

The influence of rod light and dark adaptation upon cone mediated spatial acuity was studied in the near parafoveal retina of normal human observers. The luminance just necessary to detect squarewave test gratings of variable frequency provided an index of spatial acuity. Such thresholds were determined in the presence of background fields which were varied in luminance, shape, and size, or throughout the time period of dark adaptation. Spectral controls determined the type of photoreceptors influenced by all stimuli. Cone mediated spatial acuity is improved by presenting background fields too dim to directly affect cones, and is increasingly suppressed during the rod recovery stage of dark adaptation. These effects are small with spatial frequencies less than 4 c/deg but increase with spatial frequency to greater than 1 log10 unit with the highest spatial frequency examined, 21 c/deg. These influences upon cone mediated spatial vision reflect the state of long-term adaptation of rods in a large annular area surrounding the locus to which the test grating is presented. Our results emphasize the differing influences of long-term dark adaptation and prevailing luminance level upon visual acuity. Ironically, spatial acuity is optimized under dim light conditions by selectively light adapting the receptors most sensitive to feeble stimuli, the rods.

Adaptation, Ocular↗