摘要:

A special application of electrical impedance plethysmography called impedance cyclography is defended as an indicator of ciliary muscle contraction during accommodation. Comparison of ciliary muscle impedance change to changes in lens cur vature and refractive power are presented. Mechanical extrusion of the blood from the ciliary muscle during accommodation is held to be the direct cause of the electrical impedance change.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Stereoscopic depth was measured in central vision under photopic viewing conditions. Two test lines, one appearing above the other, were briefly exposed and adjusted to match in apparent depth. The standard deviation of the subject's settings provided the depth threshold. Log threshold increased roughly linearly with increasing disparity. The exponential rise in depth threshold with increasing disparity was thus verified. Previous authors working under mesopic conditions and at great peripheral angles, found a steeper increase in depth threshold as a function of disparity for the more central angles. The present results showed that the stereoscopic response behaves differently under photopic conditions and peripheral angles up to 1.3 deg arc, as the slopes of the straight lines fitting the data sets from different angles within central vision were not found significantly different. Subjective depth equality settings resulted in physical equality for small disparities, and stereoscopic matching can therefore be performed with great veridicality. But for greater disparities, an anisometric relation between retinal areas above and below the horizontal meridian became apparent.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

We report an experiment in which the evoked cortical potentials (VER) have been measured in an attempt to assess the best refractive state at various wavelengths. The measurements have also been carried out subjectively on the same subjects. It was thus found that the chromatic aberration of the eye can also be determined by the evoked cortical potentials, within about 0.5 D, in our small sample.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

A paired-reading study was performed to determine the effectiveness of the Applamatic tonometer as a clinical instrument by comparing its findings to Goldmann tonometric readings. The results reported that the instrument is a poor indicator of the Goldmann findings. There was no difference in whether a scleral or corneal site of application was chosen for the Applamatic.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

In the United States today there are 1.64 million people who are partially sighted and not blind. One important visual aid that has long been ignored by clinicians and others who serve the partially sighted are binoculars. These can be used in the home, in school, while traveling and in many aspects of normal everyday life. Binoculars can be supplemented with specialized equipment to extend and improve their use for a greater variety of visual deficiencies. Although binoculars may not be useful to all partially sighted people, the author urges clinicians to become knowledgeable of this aid and its potential, in the interest of expanding the visual horizons and capabilities of the partially sighted population.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

An eleven-year-old boy with a complaint of double vision was examined. A diagnosis of myasthenia gravis was made.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

Recent literature has emphasized the increased prevalence of diabetes mellitus and blindness due to diabetes. The prevalence of diabetes and incidence of blindness due to diabetes is discussed in light of recent data and various criteria used for ratings. It appears that although diabetes may now be the leading cause of new blindness, it is not the leading cause of total blindness.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

摘要:

A rhythmic local pulsation of the light reflex in the arterial segment of the retinal vasculature is described. This sign, reported for the first time, is seen in the first order of the retinal arterial trec among aged patients with advanced grade three arteriosclerotic retinopathy.

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1974

数据来源: OVID