RECOMMENDED PRACTICE: LIGHTING AND THE VISUAL ENVIRONMENT FOR OLDER ADULTS AND THE VISUALLY IMPAIRED
|Publication Date:||1 January 2020|
As the workforce ages the need for lighting guidance becomes more of a concern. It seems clear that the Baby Boomer generation (born in the years 1946 through 1964) will see aging very differently from their parents. They will take their current life styles and modify them slightly but will expect to continue contributing to society and be visible in day-to-day life. This group will represent more than one in four Americans.
It should also be noted that according to the World Health Organization, the entire world, with a few exceptions, is aging, and governments are not prepared for the growth of the older adult population or how to care for them. A brief search of several industrialized countries determined that there are few regulations addressing senior vision and lighting needs and prior editions of IES RP-28 have been reported the document of choice by designers when seeking guidance in how to provide adequate light and meet the visual environmental needs for older adults in all settings.
The IES Aged and Partially Sighted Committee has worked to make this current Recommended Practice document inclusive of current research and design practice for the above population to help them maintain a quality of life into their third age. Loss of independence has been identified as the greatest fear of aging, so today's senior will be looking for answers to maximize their aging vision.
Current codes and standards are based on the needs of younger people. Steps have already been taken to begin the transition to recognizing the needs of older people. Of major importance to achieving higher lighting levels while still complying with energy restraints is the adoption of ASHRAE/IES Standard 90.1-2013 and its subsequent updates. Work by this committee's members along with the ANSI/ASHRAE/IES Lighting Subcommittee has succeeded in getting the lighting levels described in Table A-1 (see Annex A) adopted as an accepted compliance method for licensed senior living communities. This acknowledgement that senior populations have a high incidence of vision impairment and therefore require higher lighting levels was achieved by extensive investigations of 10 senior living environments. This research showed that the lighting levels in this document are being followed in the test buildings and that a higher lighting power density (LPD) was justified to meet the needs of those with vision impairment.
It should be recognized that the Americans with Disabilities Act 2010 (ADA) and the Architectural Barriers Act inadequately accommodate the needs of people who are blind and especially those with low vision.4 The ADA includes Braille, but people who develop low vision later in life may not know Braille. This document is intended to increase the designers' understanding of age-related vision loss and the importance of their design decisions that could affect the safety and independence of this growing sector of the population.
This edition has a section devoted to light for human health (see Section 6 Light for Health), including vitamin D synthesis and circadian rhythms. Recent research has identified the special cells in the human retina that receive and transmit specific wavelengths of short (blue) visible light (450 to 500 nm) to the suprachiasmatic nucleus (SCN) in the hypothalamus, which controls human circadian rhythm.5 The fact that a large number of older adults experience circadian rhythm disturbances, underscores the importance of understanding and addressing this critical bodily function. Circadian rhythm entrainment and vision may be equally important elements for safety and quality of life for older adults and the low vision population. Circadian disruption has been tied to numerous serious diseases, such as cancer, diabetes, high blood pressure, and much more.
In recent years, much has changed in many fields affecting senior living. In lighting, the biggest game change has been the introduction of LEDs and the rapid adoption by the general public and design professionals. The unique qualities of LED technology have allowed some long sought after lighting solutions to be easier and simpler. It is now possible to change correlated color temperature (CCT; the "warmth" or "coolness" of the light) to mimic the color changes of daylight throughout dawn, day, and dusk to help stabilize circadian rhythms. There is now a mechanism to help meet energy requirements and help senior environments to be more sustainable. The future for LED advances appears almost unlimited, which bodes well for the steady improvement in the quality of life for those in this population.
It is important to note that other IES Recommended Practice documents provide valuable information on vertical and horizontal illuminance values, but these do not address the needs of those with vision impairment. Rather, the reader is directed to Table A-1 for the recommended illuminance values.
The guidance provided in this document is intended to serve a wide range of users, including individuals, design professionals, owners and managers of commercial buildings, code and regulatory agencies, and legislative bodies. It is well understood that healthcare costs will increase as the elderly population ages. As the society braces for this huge economic impact, appropriate lighting and a supportive visual environment should be considered as a preventive measure to reduce the risk of falls, sleep disorders and long-term care, and therefore given a top priority by all code officials, governmental agencies and the tax-paying public.