摘要:

A new optometer that utilizes optically simulated distance line and letter targets, focusable by patient or operator, is described. Refractive findings for 376 eyes tested on the new optometer were compared with the findings obtained by conventional clinical methods. Most differences were within the limits of repeatability reported for conventional refraction tests.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

The details of our previously described theory of how the endothelium controls corneal hydration in the absence of the epithelium are provided. A central postulate is that the endothelium can produce across its limiting plasma membranes an osmotic gradient that reduces stromal swelling pressure so that it does not exceed intraocular pressure during thinning of a swollen cornea.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

A previous study using photoelectric retinoscopy at near showed an increase in fundus reflex luminance when the subject's task was changed from reading simple material to adding numbers. Unfortunately, it was not possible to attribute the luminance change to the change in cognitive task. The present experiment was designed to determine whether an increase in cognitive processing would produce an increase in fundus reflex luminance. When the subjects (N = 19, ages 22 to 27) changed from viewing 2-digit numbers at 40 cm to adding the digits, with no change in the visual stimulus, the luminance increased in 47 of 54 trials –the mean luminance increased approximately 10% (p < 0.01). This change in fundus reflex luminance is not attributed to change in eye position but rather to a decrease in accommodative lag.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

The effect of viewing time on the threshold for depth and form discrimination using random-dot stereograms has been investigated. For 12 subjects the relation between logarithm of threshold disparity and logarithm of viewing time was linear for both depth and form discrimination, but the threshold for form discrimination was approximately twice the threshold for depth discrimination. Stereo thresholds determined with random-dot stereograms were not significantly related to stereo thresholds measured with a Howard-Dolman apparatus.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

In a study comparing the Screening Test for Young Children and Retardates (STYCAR) and the New York Lighthouse Flash Card Test, 50 preschool children (median age of 4.4 yr) were evaluated twice with each instrument. Results indicate that the Lighthouse test had higher reliability, better visual acuity scores, lower untestability rates, and shorter testing times than the STYCAR.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Psychophysical measures indicate that man's perception of short-wavelength (blue) radiation continually diminishes from birth until death. This essay reviews anatomical and psychological data and discusses the practical and experimental significance of this development during the life cycle.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Dynamic measures of vergence accommodation (VG-ACC) are necessary for complete analysis of the triadic near response but are difficult to obtain because eyeball rotation affects accommodative measures. A dynamic optometer that uses the third Purkinje image is shown to be insensitive to small eye rotations and permits dynamic measures of VG-ACC responses. Such measures are presented to demonstrate the feasibility of this method. Average latency measures of 260 msec for VG-ACC fall between the latency of 160 msec for disparity vergence and the latency of 380 msec for accommodation. Additional dynamic features of VG-ACC resemble those of other components of the near triad.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Measures of horizontal phoria, vergence, and fixation disparity were obtained for 2 samples: 28 optometry students without symptoms and 32 orthoptic patients with symptoms associated with binocular oculomotor difficulties. Discriminant analysis was used to determine which tests or group of tests best discriminated between the 2 samples. Analysis was done for both samples and for exophoric and esophoric subsamples. Sheard's criterion was the best discriminator for the exophoric group, and amount of heterophoria was the best discriminator for the esophoric group. Fixation disparity was the next best discriminator for both groups.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

A 4-year-old boy with uncorrected anisometropic indirect astigmatism showed amblyopia and strabismus. Over a period of approximately 3 yr, neutralization of the refractive error and treatment of the amblyopia and strabismus resulted in single binocular vision with good stereopsis. The results suggest that at least up to age 7 the visual system is sufficiently plastic to be modified by treatment.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID

摘要:

Articles on the retina which appeared in the/Amer/can Journal of Ophthalmology, Archives of Ophthalmology, and British Journal of Ophthalmology from July 1975 to June 1976 are summarized. Topics include a specific receptor for retinol-binding protein, retinal pigment epithelium, retinitis pigmentosa, diabetic retinopathy, infections, degenerations, maculopathy, sickle hemoglobinopathy, retinoblastoma and retrolental fibroplasia, and macular hole and retinal detachment.

ISSN:0093-7002    

出版商:OVID    

年代:1977

数据来源: OVID