ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Astigmatism was measured retinoscopically for 709 subjects residing in an institution for the mentally retarded and for 56 noninstitutionalized mentally retarded subjects at a community training center. About 60% of the subjects were between 15 and 45 years old. Compared to an intellectually normal sample of young men, astigmatism in the mentally retarded was greater in frequency and degree. For subjects with greater degrees of mental retardation, the prevalence of high astigmastism was significantly greater for whites than for nonwhites. There was no difference in astigmatism between institutionalized retardates and those living in a community setting, a finding that implies that the institutional environment was not the cause of the astigmatic differences between retarded and normal subjects.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

A 3-week visit to the People's Republic of China revealed a need for more eye examinations and professionally dispensed spectacles. Although health care is well organized and widely distributed, especially considering the current stage of economic development, vision careper sewill need upgrading as the society becomes more economically efficient and technologically developed.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

This paper explains why the accommodative response to near objects is ineffective through a telescope. A simple formula is used to demonstrate the need for a bifocal spectacle objective or a change in vertex distance when viewing near objects with a contact lens spectacle lens telescope. Using this exact formula, clinicians can now more precisely compare refractions with and without a telescope. The formula also shows why refractions with telescopes used for driving should be accomplished at test distances of 20 feet or more.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

This paper reports a series of tests of the assumptions entailed in the random spatial disparity hypothesis (Tyler, 1974) of the stereophenomenon that occurs on viewing dynamic visual noise with an interocular delay. The results support the hypothesis in opposition to 2 alternative hypotheses. A new stereophenomenon is reported in which reversed steromovement is perceived when viewing dynamic visual noise that has both an interocular delay and complementary contrast between the 2 eyes. Only the random spatial disparity hypothesis appears to account for this reverse stereophenomenon.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Simple onset response time (RT) experiments, previously shown to exhibit binocular summation effects for white stimuli along the horizontal meridian, were performed for red and green stimuli along 5 oblique meridians. Binocular RT was significantly shorter than monocular RT for a 45-min-diameter spot of red, green, or white light within eccentricities of about 50 deg from the fovea. Relatively large meridian differences were noted that appear to be due to the degree to which the images fall on corresponding retinal areas.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID