commodations lower the risk of occupational injuries found by Zwerling et al. (1998a) among older workers with various impairments.

We adopt here the control hierarchy as an approach to beginning a discussion of the current status of intervention strategies to meet the safety and health needs of older workers. While there is some specific evidence to support this approach, it is limited (e.g., older adults are more likely to read warnings but less likely to comprehend warning signals [Rogers and Fisk, 2000]). Therefore, we use the concept as a useful way to structure and present ideas for accommodating the needs of older workers without arguing for a rigid order of preference. Interventions relevant to all workers, but particularly for older workers, also include workplace design and redesign; worker training; learning systems and retraining issues; alternative forms of work; the relation of the workplace to community service support; worksite health promotion and illness or disorder prevention programs; and employee assistance programs, including return-to-work programs.

JOB DESIGN AND REDESIGN

In keeping with the breadth of potential workplace interventions noted in the introduction to this chapter, we now consider job design, including redesign and engineering, to improve the accommodations for older workers. There are many well-documented cross-sectional studies and some longitudinal ones outlining normative changes in vision, hearing, physical strength, and flexibility with age, as examples for requisites for many work environments (see Chapter 5). Some data derive from representative national samples. These age-related changes can be expected to affect older workers if they cannot compensate for such changes. Nonetheless, to the extent that work in the future requires maximal performance rather than typical performance, and if older adults retire later or return to part-time work after retirement, design interventions will probably become necessary.

Design Interventions to Accommodate Normative Changes in Vision

There are a variety of normative changes in vision with increased age (see Fozard and Gordon-Salant, 2001, for a review). Prominent among these are loss of accommodative power for the lens (near-vision focus), yellowing of the lens that weakens color discrimination, scattering of light in the eye due to debris in the vitreous humor, and inability to expand the pupil fully (senile miosis). Most of these changes result in less light being admitted to the eye—about one-third as much light comparing a 65-year-old to a 20-year-old in low light conditions. Due to increased scattering of light, there is also greater susceptibility to glare from light sources. There



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