摘要:

A survey of the recent vision literature was conducted to obtain information about spontaneous activity in visual systems. Contemporary facts and speculations on three general topics are reviewed: (a) the characterization of, and the variation in, spontaneous activity: (b) the genesis of spontaneous activity in the visual systems; and (c) the role which spontaneous activity is thought to play in visual information processing.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Similarities, differences and interactions among color and shape variables were studied using a tachistoscope and partial report procedure. Results indicated a decrease in information with an increase in delay time for all conditions. All subjects processed color information more effectively than shape information. For the combined color-shape condition, one subject used both color and shape clues effectively and one subject showed no significant difference between his color decay function and his color-shape decay function. The possible implication of this visual information processing approach to human performance in the classroom is discussed.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Fifty-two optometry students exhibiting various refractive errors determined their own spherical correction by observing, through a phoropter, a defocused laser beam projected on a slowly rotating drum. Their task was to adjust the amount of sphere in the phoropter until the speckle pattern of the laser appeared stationary. Each observer made 20 monocular settings using his dominant eye. The data were analyzed for each refractive type (emmetrope, myope, hyperope) in terms of their variability, and it was found for all refractive groups that the phoropter settings were highly reliable. The data showed that when neutrality was approached from a simulated myopic refractive state (over correction with plus) the reliability for all groups was higher than when the initial simulated refractive state was hyperopic (over correction with minus). The results also indicated for all groups that adjustment of the lenses from an initial over correction with plus resulted in less minus correction than when they were adjusted from an initial over correction with minus.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Change in staining of corneal and upper lid tissues, in corneal curvature, in corneal sensitivity, and in upper lid sensitivity of a 10-year wearer were investigated systematically in one control and two experimental conditions during a 29-day period. Results showed that staining of cornes and upper lid disappeared in three days after removal of contact lens and then reappeared after reinsertion. Corneal curvature first flattened (1.25 D) and then steepened (0.50 D) after removal, and steepened and then flattened after reinsertion. Corneal sensitivity increased after removal and decreased after reinsertion, and upper lid sensitivity first decreased and then increased after removal, and decreased reinsertion.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The hydration course from standard room conditions to saline saturation at 288 hours was followed for a common contact lens plastic. Mass was found to increase by 1.4%, axial length by 0.5% and face dimensions by 0.4%.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

In this paper the aspherical deformation and its variation across the surface of symmetrical aspheres, which can be used as lenses with variable refractive power for the correction of presbyopia, is approximately calculated. It is shown that the aspherical deformation vanishes in the symmetrical line and increases normal to it with the variation of the refractive power. The variation of the aspherical deformation in this direction, which can be observed as swaying and rocking of the object field with visual movement, is greatest in the region of the vertical line and decreases towards the marginal zones.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Among a junior high school population, it was found that one in four white students wore spectacles while only one in ten black students did so. The difference is significant at the 0.01 level.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Though Carl Pulfrich (1858–1927) is best known to visual scientists for the stereophenomenon which carries his name, his loss of vision in one eye prevented him from observing the phenomenon. His demonstration apparatus did not include a pendulum as is usually stated in descriptions of the Pulfrich effect. Pulfrich himself gave full credit to others for discovering the phenomenon and for the theoretical explanation. The notion that the effect could be applied to heterochromatic photometry was his own, however.A few biographical notes of pertinent interest are included.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The subjet of the report, an optometry student was found in the optometry laboratory to have an extremely high hyperphoria. Although he wore lenses for myopia, this high phoria had seemingly not been discovered previously.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

A post-surgical constant exotrope was successfully treated, via optometric visual training, despite a prior history of five separate strabismus operations.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID