摘要:

Perception is the over-all immediate response to stimulation of sense organs, the reaction that expresses the organism's relation to the environment regardless of whether this expression is consciuos or simply a gesture or other motor act that is discriminative. This conception of perception differs from that sometimes held. The historical basis for misconceptions of perception is discussed, the basis for the present concept is described, and some optomatric applications are noted.

ISSN:0002-9408    

出版商:OVID    

年代:1970

数据来源: OVID

摘要:

Sodium and potassium concentrations of the tears of six patients were monitored during adaptation to contact lenses and compared with pre-fitting levels. These two cations were found to vary independently and the implication of these vatiations is discussed relative to fitting observations.

ISSN:0002-9408    

出版商:OVID    

年代:1970

数据来源: OVID

摘要:

At the edge of a contact lens, the tear fluid interface is concave. The radius of curvature of this interface was measured on female subjects, using a slit lamp photographic technique, and the corresponding negative pressure was calculated.When the lens is pulled by an external force negative pressure draws the lens to the cornea. Adherence of the lens to the cornea is thus achieved by negative pressure. To move the lens to the flatter peripheral cornea, the lens must be lifted against negative pressure: negative pressure draws the lens back to the optical zone of the cornea. Thus both adherence and centralization are accomplished by means of negative pressure.

ISSN:0002-9408    

出版商:OVID    

年代:1970

数据来源: OVID

摘要:

This paper presents a brief discussion of recent accounts of the effects of stimulus wave-length on the waveform of averaged human visual evoked cortical potentials. Some new data are presented which do not exhibit gross waveform changes with stimulus wavelength, when all monochromatic stimuli are equated for brightness.

ISSN:0002-9408    

出版商:OVID    

年代:1970

数据来源: OVID

摘要:

Stereoacuity for small, parafoveal targets as a function of difference in chromatic stimuli was determined successively with narrow band red, green and blue targets. Apparatus was a modified Howard-Dolman, type needle alignment device with micrometer drive capable of accurate discriminations to ±0.05 mm. Fluorescent targets emitted narrow bandwidth spectral energy with peaks near 623, 546, and 450 nm respectively. Results indicate a systematic difference in stereoacuity under the influence of chromatic stimulus changes. Acuity with blue stimuli was lowest for all subjects: relative acuity levels for red and green varied from subject to subject.

ISSN:0002-9408    

出版商:OVID    

年代:1970

数据来源: OVID

摘要:

Electrooculography (EOG) is a common method for recording eye movements, but the EOG has not been used to any extent in optometry except for research. If a suitable EOG apparatus were available, optometrists could use it for routing clinical measurements. Such an apparatus has been developed. A description of the apparatus is presented. Several clinical tests performed with it are shown as examples of its usefulness and performance.

ISSN:0002-9408    

出版商:OVID    

年代:1970

数据来源: OVID

摘要:

A study was carried out in which evoked cortical potentials were obtained under monocular and binocular viewing conditions, with image quality and flash intensity as experimental variables. The results showed that the degree of binocular summation obtained was directly related to the quality of the image presented to the two eyes. A complex interaction was indicated between sharpness of focus and flash intensity, with the higher degree of binocular sumation being obtained with high flash intensities when defocused patterns were used. These results suggest that the most unequivocal results will be obtained with the use of low to medium flash brightnesses.

ISSN:0002-9408    

出版商:OVID    

年代:1970

数据来源: OVID

摘要:

A department devoted to announcements, reports, appointments, organization data, news, professional problems and ideals, as these relate to the Academy.

ISSN:0002-9408    

出版商:OVID    

年代:1970

数据来源: OVID

ISSN:0002-9408    

出版商:OVID    

年代:1970

数据来源: OVID

摘要:

After two drops of Ophthaine a patient reacted with extremely dilated pupils, a reaction never known before. This patient was suffering from different kinds of allergies and at the time of the visit to the Optometry Clinic was under treatment of these allergies. A cycloplegic used in an eight-year-old child caused no systemic effects but a psychic reaction.

ISSN:0002-9408    

出版商:OVID    

年代:1970

数据来源: OVID