摘要:

This report present an analysis of retinal irradiances from He-Ne gas CW lasers. Equations are developed for retinal irradiance as a function of viewing distance for typical He-Ne laser with peaks output powers of 0.5 to 100, milliWatts. The various viewing conditions are described and irradiance equations developed for each. Based on extrapolations from theoretical retinal bourn models and available experimental data several conclusions are stated. (1) Continuous exposure of the eyes to a He-Ne laser of any power in the laboratory cannot be tolerated. (2) Typical alignment He-Ne lasers in the range of 0.5 to 5 milliwatts present no retinal hazard from a momentary accidental exposures at distances beyond 300 meters anda re probably safe for continuous exposure at distances beyond 1,000 meters.

ISSN:0002-9408    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

The history of the ERG (Electroretinogram) is traced through its first recordings to present times. The origins of the ERG are discussed, leading to the potential application of this technique to clinical optometry. Of particular promise is the use of “flicker ERG.” the responses to which is of sinusoidal form. As such certain simplifications are possible, leading to the anticipation of optometric clinical electroratinography within an economically feasible framework.

ISSN:0002-9408    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

The method of Bonnet of obtaining a topographical diagram of the cornea by the use of his topographical ophthalmometer is described. By this method, the deformation of the cornea after wearing plastic (heard) contact lenses and get (soft) contact lenses was studied. The deformation of the cornea caused by gel lenses is less than that form wearing hard lenses.

ISSN:0002-9408    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

To investigate the effects, if any, of perceptual training upon selected measures of reading achievement in first grade, 12 experimental classrooms of first grade pupils, randomly selected, received a 29-day adaptation of the Frostig Program for the Development of Visual Perception while 13 control classes added comparable time to the regular reading instructional program. Analysis of the data revealed statistically significant differences between the treatment groups in most of the post-perceptual capabilities, favoring the experimental groups, without concomitant effects on reading criterion measures. While the total score from the Frostig Developmental Test of Visual Perception appeared to have a strong predictive function regarding first-grade reading, the training of visual perception subskills did not appear to have a significant effect on reading ability at the end of the first grade year. Additional findings are reported that strongly suggest the need for further research.

ISSN:0002-9408    

出版商:OVID    

年代:1968

数据来源: OVID

ISSN:0002-9408    

出版商:OVID    

年代:1968

数据来源: OVID

ISSN:0002-9408    

出版商:OVID    

年代:1968

数据来源: OVID

ISSN:0002-9408    

出版商:OVID    

年代:1968

数据来源: OVID

ISSN:0002-9408    

出版商:OVID    

年代:1968

数据来源: OVID