Changes In Visual Performance After Visual Work

Changes in Visual Performance After Visual Work

"This report critically reviews some of the experimental and field studies on the effects of prolonged visual work. It is pointed out in the report that there are two basically different kinds of visual work, one primarily involving search for infrequently occurring signals (vigilance tasks) and the other involving active continuous use of the oculomotor system and requiring more or less continuous mental operation (active tasks). The effects of work at these two types of tasks on the capacity for further visual work are different. Even relatively brief periods of time spent at visual vigilance results in a reduction in visual sensitivity. Relatively long periods of time at active tasks produce either no deterioration or very little deterioration in the capacity for further visual work unless the situation is complicated by extreme loss of sleep, anoxemia or presence of drug effects. Continuous work at active visual tasks, however, does produce depression, headaches, feelings of tiredness and irritability. Any attempt at reducing fatigue in active visual tasks should be directed towards these factors."--Abstract.

HumRRO Research Report

Visual Impairments

When children and adults apply for disability benefits and claim that a visual impairment has limited their ability to function, the U.S. Social Security Administration (SSA) is required to determine their eligibility. To ensure that these determinations are made fairly and consistently, SSA has developed criteria for eligibility and a process for assessing each claimant against the criteria. Visual Impairments: Determining Eligibility for Social Security Benefits examines SSA's methods of determining disability for people with visual impairments, recommends changes that could be made now to improve the process and the outcomes, and identifies research needed to develop improved methods for the future. The report assesses tests of visual function, including visual acuity and visual fields whether visual impairments could be measured directly through visual task performance or other means of assessing disability. These other means include job analysis databases, which include information on the importance of vision to job tasks or skills, and measures of health-related quality of life, which take a person-centered approach to assessing visual function testing of infants and children, which differs in important ways from standard adult tests.