Comparison of vertical fixation disparities between essential hypertensives and matched normotensives

Using American Optical Vectographs and a Disparometer, vertical fixation disparities and associated phorias were measured on 19 essential hypertensives and 19 matched normotensives. Subjects were matched on the basis of race, sex, age, use of tobacco, and family history of hypertension. Correlated variance comparisons of the measured associated phorias and fixation disparities, as well as calculated x and y intercepts derived from forced-duction vertical fixation disparity curves were made and a t-test for related measures was used to compare slopes. The x and y intercepts and slope data showed no significant differences between the groups. However, statistically larger measured associated phorias for the hypertensive group were found on all but one test. This suggests a relation between the magnitude of vertical associated phorias and the occurrence of essential hypertension, but the relation found was not of sufficient strength to warrant clinical application.

Comparison of Snellen letter and Vistech grating charts as refraction targets

Snellen letter and Vistech sine wave grating charts were used as refraction targets to determine differences in times required to accomplish subjective refractions, endpoint refractive values, and subject preferences. Thirty hyperopes and 30 myopes, divided into three age groups, were selected as subjects. Two examiners tested each subject using each chart. Both timed their subjective refractions and recorded their findings. After all data were recorded, each subject completed a questionnaire to determine chart preference. There were no clinically significant mean differences between the charts in terms of endpoint refractive data, but, on average, the Snellen chart was faster to use. Chart rating depended on the subject's refractive status with more myopes preferring the Snellen chart and more hyperopes rating the grating chart higher.

Chromatic imbalance due to commonly used red-green filters reduces accuracy of stereoscopic depth perception

This study was designed to determine the effect on stereopsis of interocular retinal chromatic and illuminance imbalance in 30 subjects with normal binocularity. A Randot 3 Circle Stereotest, viewed through polarizing glasses only, was the control condition. In each of three additional conditions, illuminance and chromatic imbalances were created by commonly used red and green filters and neutral density filters combined with the polarizing filters. The effect of each of these experimental conditions on stereopsis was determined by comparing total stereo judgement errors on the Randot Circle Stereotest for each condition to the control condition. Total average flux through the filter combinations was held constant by adjusting the luminance level of light reflected from the target. The chromatic imbalance created by the red-green filters significantly increased the number of stereo judgment errors (37%, p less than 0.05). However, illuminance imbalance (0.2 log units) of the magnitude created by the red-green filters did not significantly increase the number of errors (2.9%, p less than 0.65). Finally, the combined illuminance and chromatic imbalance created by the red-green filters significantly increased the error frequency (46%, p less than 0.05). The chromatic imbalance caused by red-green glasses significantly degrades stereopsis, whereas the illuminance imbalance caused by these filters has no significant effect on stereopsis.

The psychiatry of writing a will

The last will and testament of patients seen by psychiatrists is rarely a topic of exploration. On examination it is found to be intertwined with the testator's attitudes toward death. When these attitudes are irrational and conflictual, the making of a will is also a conflictual activity, revealing many bizarre strivings, especially for immortality.

Changes in optometric findings during pregnancy

Two complete optometric examinations conducted 3 months apart with 38 nonpregnant and 93 pregnant subjects (divided equally into three groups based on the trimester of pregnancy in which examinations were done) were conducted. Differences between the findings were compared by analyses of variance and t-tests. Refractive error, corneal curvature and thickness, accommodative amplitude, AC/A ratio, and fusion break ranges were not found to change significantly during pregnancy.

Properties of anaglyphic materials that affect the testing and training of binocular vision

Unequal retinal illuminances and target contrasts, and ghost images of anaglyphs can affect binocular vision. These properties were studied in red-green anaglyphic materials, and for all three pairs of red-green glasses tested, the luminous transmittance of the green member of each pair was higher than that of the red. Differences ranged from 15.3% to 33.1%. In all combinations tested, contrast was higher with the green lens when viewing red acetate than it was for the red lens when viewing green acetate. These marked differences between red and green materials are noteworthy because they can induce differences between the two retinal illuminances, thereby affecting suppression tendencies.

[Results of neurophysiologic studies in ophthalmic migraine]

The influence in 8 of our patients with ophthalmic migraine of photic driving with sine-like flashing lights on EEG background activity was checked and the visually evoked potentials following the application of diffused simple light stimuli were analyzed using the recovery cycle technique. The results indicate a slightly increased tonic activity of the structures of the mesencephalic formatio reticularis, such as may be produced by slight functional disturbances. Some vegetative secondary symptoms of migraine attacks and some of the changes in EEG observed in patients with ophthalmic migraine are explicable by such an abnormality.

Comparative monocular contributions to brightness in relation to abnormal stereothreshold

This study was designed to compare brightness contributions of the two monocular inputs to the binocular visual system at three different levels of luminance adaptation in two groups of 15 subjects each. The only known difference between these groups was stereothreshold, 50 to 70 sec arc in one group vs. 40 sec arc or less in the other group. The group with elevated threshold was found to have a significantly larger average difference (13.5%, p less than 0.002) in monocular brightness contributions, between the right and left eyes, when compared to the group with lower stereothresholds (4% mismatch). The results also indicate that neither group showed a significant variation in mismatch as adapting luminance was altered by a factor of four times (0.6 log units). Finally, no clear relation was found between eye dominance and the eye requiring higher illuminance to attain the dichoptic brightness match.

Development of psychomotor tempó (tapping speed and stability) and EEG alpha frequency in 7 to 15-years-old children

The psychomotor tempo (tapping) and its relation to alpha frequency was investigated in 100 7- to 15-year-old children. The frequency of alpha rhythm increased in proportion to age, and the maximum and preferential tapping frequencies revealed an increasing tendency, too. Mainly the preferential tapping frequency correlated with the age-dependent increment of EEG alpha frequency. Simultaneously, the variability of the tapping frequency decreased. During a phase of relatively stable tapping performance regular fluctuations in the tapping frequency occurred with a period duration between 0.67 and 13.3 s. These oscillations of the motor activity developed during ontogenesis: The slow fluctuations were found in all groups, whereas those with shorter periods were best pronounced in the older children. The development of EEG and psychomotor indices are assumed to be based on the morphological and functional maturation of the developing brain. Therefore, they may be used as a tool to assess the normal and disturbed brain development.

[Use of the labyrinth test in gerontologic functional diagnosis]

The authors inform on the basic application possibilities of the labyrinth-test in gerontological functional diagnoses. They are able to refer to experiences gained from their investigations with 365 subjects from 18 to 75 years of age (197 female, 168 male ones). They recommend this psychological procedure as a practicable and economical method to assess age-dynamics of over-lapping sub-aspects of intelligence (orientational capacity, transitional ability, problem-solutional attitude, memory performance).

[Methods for the determination of psycho-social performance within the scope of a model for objectivizing biological age]

With the help of experimental findings of a randomized study concerning the dynamics of ageing of a reference population (365 persons of either sex between 18 and 73 years) the authors adopt a principal attitude to methodical questions in objectifying the biological ageing. It is above all demonstrated, if and in how far the psycho-sociometric methods used in a gerontological complex method developed for this purpose meet certain methodical requirements (objectifity, reliability, validity) and are effective from the practical and clinical point of view. On principle it is referred to the necessity of a sex-different interpretation of findings concerning the dynamics of ageing and to the possibilities and borderlines, to attract them for a total assessment of the performance. The clinical model demonstrated for objectifying the biological ageing of man opens a wide field of theoretical and practical possibilities to gain recognitions on dynamics and influencibility of human ageing.

Loneliness and the poet: Robert W. Service

The subject of loneliness has received inadequate attention at the hands of psychoanalysts. As a matter of great psychopathologic significance, the topic requires urgent attention. Its components and consequences are more complex than one realizes at first glance. As a great concern of mankind loneliness is naturally seized upon by poets, who dwell upon it in their work, whether or not they are consciously aware of it. These points have been studied in this essay by a scrutiny of the life and work of the poet, Robert W. Service.

Comparative monocular brightness contributions in normal binocular observers

In order to find out whether equal monocular light stimuli result in equal monocular brightness sensations in normal binocular observers, one-half of a bipartite field presented to one eye was matched to the other half seen by the opposite eye while a binocular surrounding field maintained constant adaptation. Ratios of monocular luminances required for brightness matches showed an overall average mismatch of 2% (SD = 2) in 12 subjects. This value is significant at the 0.01 level, and only one subject showed a mismatch greater than 6% (more than 2 SD from the mean). It is concluded that about two-thirds of normal binocular observers would be expected to show monocular contributions to brightness that match each other within 4% or better.

A non-polarized alternative to polarized nearpoint test cards

Refractive balance at near is feasible with an inexpensive, nonpolarizing device that yields data which compare favorably with polarizing methods. The device described here differs from the Turville system in that it provides a fused central field flanked by right and left peripheries that are seen monocularly. Among the advantages are simplicity, ease of alignment and low cost.