ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The spherical component of refractive error was measured subjectively before and after noncontact tonometry in 19 eyes and also on the fellow (control) eyes without tonometry. No significant change in this measure of refractive error was found after tonometry. The tested group could not be distinguished from the control group.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Experienced alcohol and marijuana users were instructed to track with their eyes a small spot that moved horizontally back and forth in pendular (sinusoidal) motion across a 7.5-degree field. The frequency of spot oscillation was gradually increased from 0.5 to 3.0 Hz in 40 sec. Eye movement recordings showed the frequency at which smooth tracking and, soon thereafter, saccadic tracking broke down. These smooth and saccadic cutoff frequencies were reduced after administration of alcohol, but not after marijuana or placebo. For low alcohol doses, smooth tracking was impaired and saccadic tracking was unaffected, much like an effect previously reported for barbiturates. Alcohol seems to affect smooth tracking by increasing the central processing time required to generate the appropriate eye movement. It affects saccadic tracking by slightly decreasing saccadic velocity and to a greater extent by increasing latency time, part of which may be devoted to central processing. The site of action of alcohol appears to be central to both the paramedian pontine reticular formation and the flocculus of the cerebellum.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The mydriatic effects of several concentrations of phenylephrine and of tropicamide were studied in 84 young adults for 90 min following topical instillation. Pupillary diameter was estimated (a) under ambient photopic illumination and (b) when illumination was increased to that associated with direct ophthalmoscopy. Evaluation was made of the “degree of mydriasis,” i.e.; the difference in pupillary diameter between the eye receiving the mydriatic agent and the contralateral control eye when the pupillary light reflex was stimulated. In subjects with light or hazel irides, phenylephrine caused maximal dilatation in 60 to 75 min, mean values being 5.6 mm with 1 drop of 2%, 6.0 mm with 2 drops of 2.5%, and 7.1 mm with 1 drop of10%. Maximum degrees of mydriasis were 3.0 mm with 2 drops of 2.5% and 3.1 mm with 1 drop of 10%. With 0.5% tropicamide, maximum diameter was 8.0 mm in 30 min in subjects with light, hazel, or brown irides, and the maximum degree of mydriasis was 5.0 mm. It is concluded that when a mydriatic agent is used to facilitate intraocular visualization, neither specification in terms of (a) maximum diameter under ambient illumination nor (b) degree of mydriasis provides optimal characterization. It is suggested that the “clinically effective diameter,” i.e., pupillary diameter under illumination corresponding to that to be used during examination, would be the most useful specification.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Hering's Law of Equal Innervation treats the double eye as a single organ. Normal humans often execute saccadic eye movements that are dynamic violations of Hering's Law. These infractions are produced by differences in the neural controller signals sent to each eye and are exemplified by monocular movements, such as dynamic overshoot, glissades, and double saccades; these dynamic violations occur more frequently in fatigued subjects. In contrast to dynamic violations, static violations of Hering's Law are usually indicative of pathological conditions.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Behavioral and developmental optometry are in need of research. Studies conducted by optometric students can provide a major contribution. The present paper reviews selected student research studies conducted at the Illinois College of Optometry. The topics include: trends in developmental vision, phenomena in binocular vision, and techniques in diagnosis and treatment.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Multivariate techniques were used to explore the relationship between ocular dominance and asymmetries in visual acuity or acuity dominance. The convergence distance under which the acuity testing takes place was found to affect the relationship between these two variables.

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0093-7002    

出版商:OVID    

年代:1976

数据来源: OVID