摘要:

A discussion of the legal definition of blindness is given and some of its shortcomings are revealed. This is followed by the development of a functional classification system of the visually impaired which divides that population into four categories, namely, (1) the functionally blind, (2) the functionally sighted, (3) the functionally sighted with aided mobility, and (4) the functionally sighted with neither sighted literacy nor sighted illiteracy.The need for a functional classification system is then argued. This includes a discussion of the current plight of the visually impaired. Emphasis is placed upon the unfortunate consequences that have arisen as a result of (1) a failure on the part of the general public, as well as many officials of public and private organizations that serve “the blind,” to recognize the heterogeneity of the visually impaired population and (2) the misapplication of the legal definition of blindness.Recommendations are then made which the author believes will tend to clarify the nature of the visually impaired population, improve public understanding of the capabilities and needs of its members, improve the quality and quantity of the services they receive from public and private organizations, and increase their chances of receiving a high quality and relevant education and achieving economic independence.

ISSN:0002-9408    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Illuminated retinas lose less sodium immediately after, and in the first minute after illumination, and more sodium three minutes after illumination than retinas that had not been illuminated. These data indicate that a sodium pump mechanism has been activated within the retina later than one minute and less than three minutes after illumination, and within fifteen minutes has restored the retina to the same sodium level as the control retina.

ISSN:0002-9408    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Plus one gradients at 40 cm were performed on 10 subjects (the normal gradients). One drop of 1% pilocarpine and one drop of 10% phenylephrine were then instilled O.U., inducing in each subject a peripheral accommodative spasm without appreciably altering pupillary diameters. At the 2-diopter peripheral spasm level another plus one gradient was performed (the spasm gradients). Statistical analysis indicated that the spasm gradients were significantly lower than the normal gradients. Statistical analysis also indicated that this decrease was closely associated with the magnitude of the normal gradient. It was concluded that pilocarpine-induced peripheral spasm decreases the ACA ratio.

ISSN:0002-9408    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Keratometric and retinoscopic findings were obtained for 631 children between two and six years of age, and the frequency distribution of corneal power for its male and female components was determined. The mean corneal power was shown to be slightly higher in value than values reported for adults. The mean for females was greater than for males by an amount slightly larger than the difference reported for adult samples. The frequency distributions of the samples were normal. Both males and females from the second to the sixth year showed a trend of decreasing mean power as growth occurred with increasing age. The frequency of corneal astigmatism measured by the keratometer increased with increasing age.

ISSN:0002-9408    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Ophthalmic lenses made from photochromatic PhotograyTMglass will darken when exposed to sunlight. This paper describes the resultant transmission characteristics of PhotograyTMlenses when they have been optically coated on the emergent surface. Optical coatings of various color densities used for sunglasses have been evaluated. The data suggest guidelines for optometric use of this combination of absorptive materials.

ISSN:0002-9408    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Effects of frame tilt and head tilt on the perceived vertical were investigated. Twenty-five male subjects aligned the rod to vertical while the frame was erect or tilted, and while the head was tilted. Results showed, first, a highly significant difference in the perceived vertical between the frame erect and tilted, with head erect, but no difference between head erect and tilted, with frame erect, implying that visual factor was more dominant than the postural; and, second, that a bare frame is sufficient to serve as a visual framework for the perception of verticality regardless of whether the visual field or peripheral cues are present, and that a relatively small size frame can serve just as well. Thus it may mean that the whole visual field is not necessary in the perception of verticality, and all that is needed is a kind of visual-anchor.

ISSN:0002-9408    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Corneal edema is a common problem associated with contact lens wear. With respect to tears and tear flow, this edema seems to be of two types, stromal and epithelial. Slit lamp studies indicate that osmotic imbalance is primarily responsible for epithelial edema, while oxygen deprivation results in stromal edema.

ISSN:0002-9408    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

A study was made to check the reliability of dynamic retinoscopy findings in a modification of the bell retinoscopy technique. The study was to compare findings between two examiners, the authors. Selected subjects in the test sample were retested to determine if the retinoscopy techniques were a variable. One examiner was measuring the light shadow edge of the beam with rather large sweeps of the instrument. The other was measuring the very center of the beam with very small, rapid sweeps of the instrument. The re-test data confirm that the technique differences could account for at least 3.50 D difference at the 40 cm test distance.

ISSN:0002-9408    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

Recent research endeavors in psychology have greatly explored depth perception through new methodological approaches. This review of the literature considers comparative studies of animals, human depth perception in infancy and early childhood, relevant depth cues, and deprivation studies, emphasizing the differential roles of innate capabilities and environmental experience.

ISSN:0002-9408    

出版商:OVID    

年代:1971

数据来源: OVID

摘要:

High school students were screened for defects of binocular vision by a new method which utilizes a mirror and spectacles which have polaroid filters placed ninety degrees apart for each eye. The results were compared to the findings that were determined by use of the Modified Clinical Technique.

ISSN:0002-9408    

出版商:OVID    

年代:1971

数据来源: OVID