Dark focus, dark vergence and subjective reports of visual fatigue during CRT display viewing

1984 ◽  
Author(s):  
Keith S. Karn ◽  
Donald H. Mershon
2009 ◽  
Vol 14 (3) ◽  
pp. 3-6
Author(s):  
Robert J. Barth

Abstract “Posttraumatic” headaches claims are controversial because they are subjective reports often provided in the complex of litigation, and the underlying pathogenesis is not defined. This article reviews principles and scientific considerations in the AMAGuides to the Evaluation of Permanent Impairment (AMA Guides) that should be noted by evaluators who examine such cases. Some examples in the AMA Guides, Sixth Edition, may seem to imply that mild head trauma can cause permanent impairment due to headache. The author examines scientific findings that present obstacles to claiming that concussion or mild traumatic brain injury is a cause of permanent headache. The World Health Organization, for example, found a favorable prognosis for posttraumatic headache, and complete recovery over a short period of time was the norm. Other studies have highlighted the lack of a dose-response correlation between trauma and prolonged headache complaints, both in terms of the frequency and the severity of trauma. On the one hand, scientific studies have failed to support the hypothesis of a causative relationship between trauma and permanent or prolonged headaches; on the other hand, non–trauma-related factors are strongly associated with complaints of prolonged headache.


2015 ◽  
Vol 20 (1) ◽  
pp. 9-11
Author(s):  
Richard Katz

Abstract This article presents a case report regarding a 34-year-old obese male who works as a chipper and grinder at a steel manufacturing mill and uses high-frequency vibratory power tools. He presents with typical complaints of carpal tunnel syndrome, including numbness in all five digits, wrist pain, nocturnal awakening/numbness, and others. Two-point discrimination (2PD) using a caliper was tested in the digits of the upper extremities and was 5 mm throughout. 2PD first appeared in the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fifth Edition, and the Sixth Edition states, “sensory deficits can be challenging to grade, since the clinical examination is based on subjective reports by the patient. Grading is based on the results of sensibility testing and two-point discrimination, to improve inter-rater reliability.” The discussion of “sensibility” involves a concept of sensory perception that is more appropriate in surgery literature than neurological literature, and the discussion of the case report in this article reflects the recent literature regarding 2PD as a measure of sensibility. The authors report that sensibility is not a simple recovery of sensory function following nerve injury but rather is a complex interaction between nerve recovery and modulation of central nervous system function in spinal cord, subcortical, and cortical structures. The authors ask if the value of 2PD in the clinical assessment of impairment has been overrated within the AMA Guides, as was range of motion in the assessment of spine impairment.


2008 ◽  
Author(s):  
Jeffrey K. Boman ◽  
David P. McCabe ◽  
Amanda E. Sensenig ◽  
Matthew G. Rhodes ◽  
Meghan T. Lee

2017 ◽  
Vol 2017 (5) ◽  
pp. 48-53
Author(s):  
Minghan Du ◽  
Yue Liu ◽  
Yongtian Wang ◽  
Bochao Zou
Keyword(s):  

Author(s):  
NYu Mal’kova ◽  
MD Petrova

Summary. Introduction: Visual fatigue is caused by changes in the muscular apparatus and retina of the eye and is characterized by deterioration in their functional activity. Along with an increase in work experience and age, workplace visual stress promotes the loss of performance. Known methods of visual fatigue prevention and eye strain relief are ineffective. In this regard, a technique of relieving visual fatigue using scattered low-level red laser radiation was developed and patented. The purpose of our study was a retrospective evaluation of effectiveness of the visual fatigue reduction technique. Materials and methods: We examined two groups of women (PC operators and jewellers) aged 43–57 years experiencing visual stress at work and practicing the method under study over the previous 20 years. The state of daylight vision was assessed by adaptation time. Results: A five-day testing of the method of visual fatigue relief showed stabilization of the light sensitivity threshold throughout the work shift. Over the 20-year period, the female workers had had no complaints of eye strain, burning or lacrimation. Objective studies of the functional state of the organ of sight showed that the light sensitivity threshold during the working day in two study groups was significantly lower than that in the control group with no preventive measures taken. Conclusions: We established that using the technique of eye strain relief based on a two-minute binocular exposure to red laser radiation with the power density of 2×10–7 W/cm2, a 5-day course every six months over the period of 20 years, helped retain retinal activity in terms of light sensitivity, thus preventing visual fatigue.


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