Video displays, work, and vision / Panel on Impact of Video Viewing on Vision of Workers.

Format:

Book

Contributor:

National Research Council (U.S.). Panel on Impact of Video Viewing on Vision of Workers.

Language:

English

Subjects (All):

Video display terminals--Health aspects.

Video display terminals.

Vision disorders--Etiology.

Vision disorders.

Physical Description:

1 online resource (287 p.)

Edition:

1st ed.

Place of Publication:

Washington, D.C. : National Academy Press, 1983.

Language Note:

English

Summary:

Along with the widespread use of computers have come growing fears that working in front of video display terminals (VDTs) can irritate and even damage the eyes. Separating scientific fact from popular opinion, this report takes a critical look at the link between VDT use and eye discomfort and disease as well as at changes in visual performance and oculomotor function. Drawing on information from ergonomics, illuminating engineering, and industrial and organizational psychology, the report gives practical advice on optimal workstation design to improve the comfort, performance, and job satisfaction of VDT users.

Contents:

Video Displays, Work, and Vision

Copyright

Preface

Contents

Executive Summary

1 Summary of Findings

INTRODUCTION

Background

Focus of the Study

Organization of the Report

The Literature Base

The Nature of VDT Work

FIELD STUDIES OF VDT WORKERS AND WORKSTATIONS

Studies of Radiation Emission from VDTs

Cataracts

Field Surveys Based on Self-Reports of VDT Operators

EQUIPMENT AND WORKSTATION DESIGN

VDT Design and Display Quality

Lighting and Reflections

Human Factors

THE CONCEPT AND STUDY OF ''VISUAL FATIGUE

JOB DESIGN AND PSYCHOSOCIAL STRESS

DESIGN, PRACTICE, AND STANDARDS

Principles of Good Design and Practice

Public Education

Standards and Guidelines for VDT Use

RESEARCH NEEDS

2 Critique of Survey Methodology

SURVEYS OF VDT USERS

Adequacy of Theory

Adequacy of Research Design

Adequacy of Measurement

Adequacy of Sampling

Unanswered Questions

RESEARCH DESIGN CONSIDERATIONS

Control and Choice in Studies of VDT Physical Parameters

Practical Considerations

3 Radiation Emissions and Their Effects

TYPES AND LEVELS OF RADIATION EMITTED BY VDTS

Studies of Emission Levels

The 1977 NIOSH Study

The Bell Telephone Laboratories Study

A Collaborative Study

Two European Studies

The 1981 NIOSH Study

The Bureau of Radiological Health Study

Radiation Safety Standards

VDT Emissions and Ambient Radiation

BIOLOGICAL EFFECTS OF RADIATION

Ionizing Radiation

Nonionizing Radiation

Ultraviolet Radiation

Visible and Infrared Radiation

Radio Frequency Radiation

Skin Rashes

VDT USE AND CATARACTS

Prevalence and Causes of Cataracts

The Evidence Regarding VDT Use and Cataracts

The Claims

Response to the Claims

Methods of Studying Whether There Is a Relationship Between VDT Use and Cataracts.

Concurrent Longitudinal Study

Nonconcurrent Longitudinal ("Cohort") Study

Case-Control Study

Two Ongoing Studies

The NIOSH Baltimore Sun Study

The Mt. Sinai Study

Conclusions About Radiation Hazards

4 Display Characteristics

EFFECTS OF CRT DISPLAY VARIABLES

Luminance

Effects on Visual Acuity

Effects on Flicker Threshold

Effects on Visual Task Performance

Luminance Uniformity

Contrast and Contrast Polarity

Raster Structure

Resolution

Jitter and Temporal Instability

Refresh Rate and Persistence

Color

Reflection Characteristics

A Summary Measure: Modulation Transfer Function

DISPLAY MEASUREMENT: TECHNIQUES AND PROBLEMS

Measurement Techniques

Measurement of Various Parameters

Character Luminance

Character Contrast

Blur, Resolution, and MTF

Standardization

FLAT-PANEL DISPLAYS

Dot-Matrix Display Variables

Character Size Effects

Character Formation

Contrast

Font

Information Density

Dot-Matrix Display Quality Measures

Advantages and Disadvantages of Flat-Panel Displays Compared with CRTs

FILTERS FOR VDTS

Kinds of Filters

Circular Polarizer with Antireflection Coating

Neutral Density Filters

Notch or Color Filters

Directional Filters

Evaluation of Filters

General Comments

Effectiveness of Filters

5 Lighting and Reflections

ILLUMINATION

Transient Adaptation

Reflections

Glare

REVIEW OF VDT STUDIES

Field Surveys of VDT Workers

Field Surveys Comparing VDT and Non-VDT Work

Laboratory Studies

6 Anthropometry and Biomechanics in VDT Applications

POSTURAL STRAIN

OVERVIEW OF BIOMECHANICAL FACTORS

Work Posture

Muscular Load

Joint Angles

Anthropometry

WORKSTATION DESIGN

Effects of Chair Design Features on the Spine.

Effects of Working Height on Postural Strain

Effects of Display Position on Postural Strain

7 Visual Tasks, Functions, and Symptoms

VISUAL ISSUES IN VDT STUDIES

Field Surveys

Visual Complaints

Measurements of Visual Status

Experimental Field and Laboratory Studies of Visual Functions in VDT Work

The Need for Job and Task Analysis

Are There Unique Features of VDT Tasks?

The Special Task of Reading

The Problematic Concepts of "Visual Fatigue" and "Eyestrain

Refractive Errors and Visual Difficulties

Myopia

OCULOMOTOR FACTORS AFFECTING VISUAL PERFORMANCE

Eye Movements

Saccadic Trajectory

Dual Mode Tracking Eye Movements

Higher-Level Eye Movement Patterns

Reading

Picture Scanning

Gaze and the Vestibulo-Ocular Reflex

Blinking

Triadic Near Reflex: Combined Focusing, Convergence, and Aperture Mechanisms

Accommodation

Dynamic Factors in Accommodation

Fatigue and Accommodation

Vergence

Pupil

Pupil as a Regulator of Light Level

Pupillary Constriction Associated with Prolonged Visual Work

Pupil as a Factor in Visuomotor Discomfort

Pupillary Hippus in Relation to Habituation and Sleepiness

Synkinesis of Accommodation, Vergence, and Pupillary Constriction

SUMMARY AND CONCLUSIONS

8 Job Design and Organizational Variables

Workers' Complaints and Job Structures

Defining Psychosocial Stress and Strain

A FRAMEWORK FOR STUDYING PSYCHOSOCIAL STRESSORS IN VDT WORK

Person-Environment Fit

Objective and Subjective Fit

STRESSORS FOR STUDY IN VDT WORK

Control

Opportunity to Control: E

Need for Control: P

Participation

Opportunity to Participate: E

Need to Participate: P

Predictability and Controllability

Unpredictable Events: E

Tolerance of Unpredictability: P

Complexity

Role Ambiguity.

Threat of Unemployment

Quantitative Workload

Prescription for Overload-Deadline Plus Delay

Responsibility for Persons

Responsibility: E

Responsibility: P

Role Conflict

Social Support

DISCUSSION AND CONCLUSIONS

9 Design, Practice, and Standards for VDT Equipment and Work

PRINCIPLES OF GOOD DESIGN AND PRACTICE

Image Quality and Display Design

Minimizing Problems Caused by Direct Glare and Transient Adaptation

Minimizing Reflected Glare and Veiling Reflections

Systematic Design of VDT Workstations

General Considerations

Specific Design and Use Guidelines

Job Design and Organizational Variables

Variation in the Task and Task Environment

Other Strategies for Good Employee Management

STANDARDS AND GUIDELINES FOR VDT DESIGN

10 Research Needs

EFFECTS OF DISPLAYS ON VISUAL ACTIVITY

Objective Correlates of Visual Complaints

Relating Display Characteristics to Workplace Conditions

Effects of Image Instability

Distinguishing Specific Effects of VDTs

PSYCHOSOCIAL STRESSORS

Appendix A A Review of Methodology in Studies of Visual Functions During VDT Tasks

Appendix B Review of a Preliminary Report on a Cross-Sectional Survey of VDT Users at the Baltimore Sun

SUMMARY OF THE NIOSH STUDY

REVIEW OF THE NIOSH STUDY

Study Approach and Methods

Introduction and Background

Design

Measures

Analyses

Conclusions

Substantive Conclusions

Methodological Conclusions and Limitations

Appendix C Dissent

Appendix D Biographical Sketches of Panel Members and Staff

REFERENCES.

Notes:

Bibliographic Level Mode of Issuance: Monograph

Bibliography: p. 243-273.

ISBN:

9786610245772

9781280245770

1280245778

9780309554428

030955442X

9780585221403

0585221405

OCLC:

427404726