摘要:

The effects of sphere and cylinder induced blur on the response characteristics of cells of the superior colliculus were explored, particularly the reduction of response efficiency to fundamental trigger features presented.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Corneal thickening was produced experimentally in two subjects by the tearing associated with a noxious simulus (grated onions or Allium cepa). The hypothesis is advanced that excessive tearing yields tears of lower than normal tonicity which in turn causes the corneal swelling.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Forty-four patients with Down's Syndrome were examined. Of these, 24 were male, 20 female; their mean age was 10.8 years and their mean IQ was 38.4. Physical features were assessed, palm and finger prints were obtained, and a detailed examination of their eyes and adnexa conducted. It was not possible to make all measurements on every patient. The data obtained in the survey are compared with the data reported in the literature. Photographs and drawings are used to show the features of interest.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

This paper presents a brief discussion of some of the optical and physiological principles to be considered when prescribing absorptive ophthalmic lenses, a comparison of the units used to describe the absorptive properties of lenses and finally, spectrophotometric charts of representative commercially available indoor and outdoor absorptive lenses grouped according to relative density, apparent color, substrate and method of obtaining absorption.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Population distributions obtained on the Nagel anomaloscope by Nelson and by Schmidt are considered. The role is discussed of inert pigments in the variability of matches on the Nagel anomaloscope and on anomaloscopes for the detection of tritanomaly. Since lens pigmentation varies systematically with age its effect can be calculated. Macular pigmentation, however, varies unpredictably between subjects and its effect in a Blue + green = Bluegreen color match can be nullified only if the mixing primaries are chosen at wavelengths for which the macular pigment densities are equal.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

A study was conducted to investigate the effects of intermittent illumination on stereopsis. Intermittency rates of 8Hz and 15Hz with pulse to cycle fractions of 1/4 and 3/4, plus steady, were utilized. A sphere-ring target with a forced choice judgment of the sphere being either before or behind the ring was intermittency being either binocular, or monocular to the dominant eye.Results from four observers indicate that the monocular intermittent condition provided the expected decrement in the 8–10Hz range that previously yielded impoverishment of visual acuity and unique changes in brightness, hue and saturation. The binocular intermittent condition also impaired stereopsis, however not in the 8–10Hz range. It was concluded that present ideas relating acuity and stereopsis are in need of revision.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Contrast thresholds (ΔL/L) were measured from the fovea to the far periphery at 2 degree intervals, along 12 meridians for a total of 1350 data points. The test spot, 10 minutes of are in diameter, was presented against a 0.85 m: background in the Harms perimeter. Contrast senstivity decreases (i.e. thresholds increase) in all directions from the fovea out to distance of 10 degrees. A broad region of equal sensitivity was found to extend from 10 degrees to 20 degrees in the superior, inferior and nasal visual fields and to 35 degrees in the temporal field. We call this region of equal sensitivity the “plateau.” Beyond the edge of this plateau, contrast sensitivity decreases at a uniform rate to the edge of the visual field. The size of the plateau remains constant in photopic, mesopic and scotopic vision (at background luminances from 8.5 × 10-5to 8.5 × 10-5mL).

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The research covers an eight year period from April, 1963, to January, 1971, and the data report the results of 6,580 tonograms taken on 2,396 patients 40 years of age and over. The report contains a description of the clinical technique of the use of the Mackay-Marg Electronic Tonometer. It establishes criteria for determining patients who are glaucoma suspects, criteria for referral, and criteria for positive diagnosis of glaucoma. It describes the method used to collect the data, a statistical analysis of the data and a discussion of the routine use of tonometry in an optometric practice. The data establish that the incidence of glaucoma increases directly with age.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The prepaid group medical practice, popularly termed Health Maintenance Organization (HMO), has been called the vanguard of American prepaid national health care. This paper examines one successful HMO in terms of organization, growth, facilities and services, and patient characteristic, with emphasis on the role of optometry in the functioning of the organization and total health care of the patient. Studies of this kind offer valuable guidance in preparing for optometry's place in prepaid health plans of the future.

ISSN:0002-9408    

出版商:OVID    

年代:1972

数据来源: OVID