Abstract

Foveal contrast thresholds of the light-adapted eye were measured for two point light sources, whose separation could be varied, and for different degrees of out-of-focus imagery. The data for sharp imagery were similar to those obtained by Van den Brink for the dark-adapted eye. It appears that for separations of the point sources from zero to about 3 min of arc the contrast threshold increases linearly. Approximately 3 min of arc (depending upon pupil diameter) is a critical angle of separation, because for greater separations the threshold remains constant. This is interpreted to indicate no overlapping of blur disks, no integration of luminous energy, and no inhibition of the two images for separations greater than this critical angle. Blurring of the images of the points increased the critical angle only slightly. This implies that the distribution of illuminance within the blurred image cannot be predicted from geometrical considerations.

© 1962 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Blurring of the Retinal Image and Contrast Thresholds in the Fovea*

Kenneth N. Ogle
J. Opt. Soc. Am. 50(4) 307-315 (1960)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (6)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (1)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription