摘要:

The relationship between night myopia under simulated night driving conditions and the dark focus of accommodation was examined. Over a range of luminance and contrast conditions typical of the night driving situation, college-age subjects accommodated to about one-half the difference between a distant simulated road sign and their individual dark focus. Subsequent laboratory and field experiments demonstrated that: (1) a negative correction equal to one-half the value of the dark focus significantly improved night visual performance as compared with their normal or full dark-focus correction, and (2) greater improvements in performance were obtained for subjects who exhibited a relatively near dark focus.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Earlier observations showed that unbuffered bathing media held by a closed chamber against the eye would become progressively more acid over a few minutes. Such shifts, however, when examined for the naturally closed eye, even for prolonged periods, were found to be within 1 pH unit of the open-eye measured average.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Eye movement patterns and reading performance were evaluated in 38 4th and 5th grade male students who were at least 1 year behind in their reading levels. Half of the subjects (Group I) demonstrated a need for convex lenses at near by a book retinoscopy criterion. The remaining subjects (Group II) showed no need for convex lenses at near by the same criterion.The subject's eye movements during reading were recorded by a commercial device called Eye-Trac. These recordings were made with 2 lens applications, piano and +0.50 D, respectively. The number of fixations, regressions, rate of reading, and relative efficiency for each condition (piano and +0.50 D) were calculated.In Group I, 3 of 5 measures showed significant improvement with plus lenses. These subjects showed fewer regressions, increased reading speed, and higher relative efficiency with plus than without. In Group II, 3 of 5 measures showed decrement with plus lenses, while 1 (comprehension) showed improvement. These subjects showed more fixations and regressions and lower relative efficiency with plus than without.It is therefore concluded that convex lenses of low power can have considerable immediate effect on children's reading skills, sometimes helpful and sometimes detrimental, and that proper pretesting with book retinoscopy will aid in the prediction of this effect.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Changes in the topography of the cornea and the contact lens during and after adaptation to Bausch and Lomb Soflenses were measured in 7 eyes by means of keratometry and photoelectric keratoscopy. Generally, little change was found in the central or peripheral surface topography for either the cornea or the contact lens. Where small changes did occur, they were found to be independent of the original corneal curvature, the fit of the lens, or the duration of wear. Significant correlations were found, however, between the additional spectacle lens power (required over the contact lens to restore maximum visual acuity) and the change in curvature of the anterior surface of the Soflens, and between the toricity of the front surface of the contact lens and that of the cornea.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

A questionnaire containing: (a) a questionnaire of physical characteristics associated with psychosomatic symptoms, (b) questions to determine the presence of myopia or hypermetropia but not the amount of error, (c) a shortened version of the Gough Adjective Check List, and (d) the Heist and Yonge Omnibus Personality Inventory were administered to 782 introductory psychology students attending Washington State University. This group consisted of 297 self-identified myopes (117males, 180 females), 439 emmetropes (207 males, 232 females), and 46 hypermetropes (15 males, 31 females). Results indicated that myopes and nonmyopes differed from one another with respect to their value systems, personality, and physical characteristics as assessed by the components of the questionnaire. Differences in these characteristics were consistently found by all assessment techniques to exist most often between myopes and hypermetropes and between emmetropes and hypermetropes rather than between myopes and emmetropes. In general myopes exhibited a personality pattern of introversion, whereas hypermetropes maintained apattern described as extroverted.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

This paper introduces new principles for the design and use of letter charts for the measurement of visual acuity. It is advocated that the test task should be essentially the same at each size level on the chart. Such standardization of the test task requires the use of letters of equal legibility, the same number of letters on each row, and uniform between-letter and between-row spacing. It is also advocated that, combined with the test task standardization, there should be a logarithmic progression of letter size. Charts incorporating these design features have been made. These charts facilitate the use of nonstandard testing distances which might be used when there is low visual acuity, when examination room layout prevents testing at the standard distance, or when it is necessary to validate visual acuity scores or detect malingering. Adjusting the visual acuity score according to the chosen testing distance is simplified by the use of logarithmic scaling

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

In some states, persons with significantly reduced visual acuity are being licensed to drive while wearing telescopic spectacle lenses (TSL.) In order to evaluate possible visual field limitations present with these devices, the peripheral visual fields of a group of normally sighted subjects were measured while they wore TSL. Severely restricted central fields and sizeable ring scotomas were present with all units tested. These results indicate that driving with TSL should be discouraged.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

A conceptual model for the natural history of learning disabilities as a health threat will be presented. The model illustrates the multitude of individual and environmental factors influencing the subsequent physical and mental well-being of disabled learners as well as the professional interaction and interdisciplinary cooperation needed to limit if not prevent the societal impact of learning disabilities.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID