Measuring light levels with photographic meters.
With proper conversion factors, light meters designed for photographic use may be used to measure clinical light levels. Conversion factors and use of these light meters are discussed.
Lighting↗
Biomedical subjects
G C Woo
Publications and source records attributed to G C Woo.
A comparison of three methods for determining the reading addition.
Three subjective determinations of the reading addition required by each of 10 subjects were obtained in this study with the use of a cross cylinder grid target, a variable color, near-point, grid target and an ordinary reading card. All three methods gave similar results. In addition, there was no change in the measurement when the color of the horizontal and vertical lines was reversed on the variable color, near-point, grid target.
Adult↗
Absolute stereoscopic thresholds as measured by crossed and uncrossed disparities.
Stereoscopic tests of 30 subjects by means of diastereo instruments showed a lower threshold for crossed disparities than for uncrossed disparities. These findings support Richards' conclusion that crossed and uncrossed disparity limits are the result of two different mechanisms.
Depth Perception↗
Panum's area explained in terms of known acuity mechanism.
Comparisons between the various types of binocular and monocular visual acuity thresholds are made in this study. The results obtained in monocular resolution and binocular diplopia experiments support LeGrand's view regarding Panum's area. Thus the physiological mechanism which appears to account for both monocular resolution and binocular diplopia thresholds could also account for a spatial tolerance which gives rise to Panum's area.
Depth Perception↗
The AO SR IIItm Subjective Refraction System: comparison with Phoropter measures.
Subjective measures of refractive error were obtained on 530 eyes using the AO SR III Subjective refraction System (operated by a trained secretary) and using a phoropter (operated by optometrists and optometry students) in a clinical setting. Comparison of these measures from the present study and from a previous study by Bannon leads us to conclude that the SR III instrument is capable of estimating refractive error with good agreement with conventional refractive methods. Comparison with the Acuity Systems 6600 Auto-RefractorTM was also made.
Adolescent↗
Comparison of accommodation with rigid and flexible contact lenses.
Measurements were made of the amplitude of accommodation for myopes wearing spectacles, rigid contact lenses, and flexible contact lenses. Both forms of contact lenses placed greater accommodative requirements on the myope than did spectacle correction, but no significant difference was found between the 2 types of contact lenses in this respect.
Accommodation, Ocular↗
The effect of hard and soft contact lenses (SoflensTM) on the spherical aberration of the human eye.
An attempt was made in this study to determine experimentally the relative effects of hard and soft contact lenses on the spherical aberration of the human eye. Results of this study indicate that there is very little difference in the value of spherical aberration between wearing soft or hard contact lenses.
Contact Lenses↗
Prescribing simple low vision aids--a case report.
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Adult↗
Spherical aberration problems.
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Contact Lenses↗
The effect of exposure time on the foveal size of Panum's area.
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Differential Threshold↗
Temporal tolerance of the foveal size of Panum's area.
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Depth Perception↗
Some of the time factors associated with stereopsis.
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Form Perception↗