摘要:

Procedures and methods for the study of the central control of accommodation by electrical stimulation are presented. Positive accommodation (an increase in the dioptric power of the eye) and negative accommodation (a decrease in the dioptric power of the eye) were found by brainstrem stimulation.The frequency threshold for positive accommodation was about 4 cps: the frequency threshold for negative accommodation about 10 cps. Frequencies of 60 and 90 cps were more efficient in producing positive accommodation while negative accommodation varied directly with the frequency up to the 120 cps limiting frequency.It is conducted that the central control of accommodation by the oculomotor nucleus depends somewhat on the stimulus frequency. Not all responses can be explained by frequency alone and a definitive theory must await further data analysis.

ISSN:0002-9408    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

The problem of the seriously retarded reader is examined to determine the role of vision. The most obvious visual factors, such as acuity and refractive error, do not seem related to the problem. Impairment of visual skills such as fusion and accommodation can contribute to reading difficulty but such defects are not primary factors in extreme cases of reading disability. Other visual functions such as form perception, visuo-motor control, and the ability to match visual and verbal configurations may be more closely associated with dyslexia.

ISSN:0002-9408    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

The time course for change of touch threshold across the lower lid margin was determined throughout the adaptation periods of four patients (eight lids). The greatest changes, up to two log10 units, took place within seven and 14 days, the primary impact point being the most rapid to adjust. Lower lid margin sensitivity previous to adaptation approached and sometimes exceeded central corneal sensitivity of the same eye.

ISSN:0002-9408    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

The translators with to express their gratitude to a woman who, working in her husband's laboratory more than a generation ago, produced a paper that is still of basic interest to today's students of color vision.

ISSN:0002-9408    

出版商:OVID    

年代:1968

数据来源: OVID

摘要:

With government becoming concerned with planned, comprehensive health services, optometrists must determine the role they wish to play in public health plans. Aspects of health plans that optometrists should consider as essential are discussed. Optometrists should maintain a cooperative attitude toward comprehensive health programs, specific areas in which such cooperation may be manifested are suggested.

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

摘要:

Early or minimal pathology of the macula may exist without observable lesions or loss of functions as measured by customary clinical tests. The photostress test is a dynamic measure of retinal function that permits detection of these subtle changes. A method is described utilizing an electronic photoflash tube to bleach the retinal photo-pigment and red illuminated Snellen letters to measure the rate of recovery of function. Data are presented on the response of 59 normal subjects and 13 showing minimal macular disease. Statistical analysis of the data is offered to support the reliability and validity of the method.

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