ISSN:0030-3755    

DOI:10.1159/000307405

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:0030-3755    

DOI:10.1159/000307406

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:0030-3755    

DOI:10.1159/000307408

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:0030-3755    

DOI:10.1159/000307410

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:0030-3755    

DOI:10.1159/000307412

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:0030-3755    

DOI:10.1159/000307415

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:0030-3755    

DOI:10.1159/000307417

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

A method is proposed for measuring the visual conspicuity of an object in its background. Associated with each object is a conspicuity area, which is defined as the retinal area within which the object to be searched for is seen in a brief presentation. The size of this area can be used as a measure of visual conspicuity. Directing attention towards a certain location in the retinal field influences the shape of the retinal area concerned. Visibility and visual conspicuity turned out to be linked by directed attention. The experimental results are interpreted in terms of external and internal determiners of attention.

ISSN:0030-3755    

DOI:10.1159/000307419

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

The efficiency of monochromatic light for the eye is expressed in the relative spectral sensitivity of the eye. In 1924, the ‘Commission Internationale de l’Eclairage’ (CIE) recommended a curve for this purpose that had to be representative for the average photopic observer. In 1931 this was incorporated in the CIE Standard Observer. The particularly important conception of luminance is defined with the aid of the relative spectral sensitivity. It is a measure for brightness and enables us to compare the light flow of sources of different color. It affords the possibility of specifying the adaptive condition under which visual tests have to be carried out. When more data became available, however, it appeared that the standard observer is less representative than initially thought. For example, its sensitivity in the blue is too low, and the spectral sensitivity of the eye proved to depend on many parameters, like field size and location on the retina. Moreover, the visual spectral sensitivities determined according to various methods prove to be mutually different. This results in the increasingly urgent question, i.e. under which circumstances a light measurement, normally based on the sensitivity of the standard observer, is adequate or not. In view of this, in the latest session of the CIE (1971) a new study of the methodologic foundations was recommended. At the same time, high priority was recommended for research into the spectral sensitivity of small fields and the specification of mesopic light. Both are of importance for perimetry and mesoptometry.

ISSN:0030-3755    

DOI:10.1159/000307420

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

In the middle of 1961 the left eye of a Bengal tiger showed signs of a keratitis and of development of a buphthalmus. The bulbi, removed post mortal in September 1968, showed pathologoanatomically the results of a perforation of the cornea and the lens of the left eye. Some histologic details are discussed.

ISSN:0030-3755    

DOI:10.1159/000307422

出版商:S. Karger AG    

年代:1975

数据来源: Karger