Design for Sight: Typologies inhibiting low vision access to interior spaces.
Presented by: Erin Schambureck, MFA, NCIDQ
Introduction: To determine how to improve perception of the interior environment for low vision users, it is important to understand the design factors that limit accessibility. By defining the primary design problems in the low vision user’s environment, designers will be better equipped to avoid these negative typologies and counteract their effects in existing spaces.
Background: 6.9% of people over age 65 have a vision disability, roughly equating to 2.5 million people over 65 with low vision (United States Census 2010). Census data also shows that by 2030 the over 65 population will outnumber the under 17 age group. As this group ages, yet strives to maintain an active lifestyle, universal design and wayfinding practices may need to expand their scope to accommodate these users in work spaces and other public settings. Universal design resources have identified low vision design solutions for residential spaces but do not call out the underlying problems that led to those solutions or how they could be adapted to commercial building types (IES, 2007). Surprisingly, the ADA Accessibility Guidelines only minimally address low vision design needs. Wayfinding is an important part of accessibility but not typically addressed by the ADAAG or universal design. It is described as a cognitive mapping experience where we assimilate information from our senses and identify paths, landmarks, zones and edges (Passini, 1992). While wayfinding addresses the concerns of a fully-sighted public, little consideration is made for the perceptual limitations of the visually impaired trying to create these cognitive maps. This research was developed to identify the underlying design problems for the visually impaired so that the findings could be applied to a variety of spaces to improve wayfinding and accessibility for all.
Methodology: First, personal accounts were collected from visually impaired users describing the difficulties they face navigating public spaces. Then, a review of the literature identified what low vision design recommendations are currently available. This research was analyzed using a coding system to identify the primary design factors impacting visual perception and the individual typologies in those categories. A space evaluation method was developed to look for these primary factors in an existing eye services clinic to verify the findings of this study. This evaluation utilized photographic, luminance mapping methods and coding analysis of user statements.
Results: Fourteen individual design typologies were identified by the research as impacting how a visually impaired user perceives interior space. These fourteen design “problems” were able to be categorized into four groups: luminance contrast, value contrast, object placement, and luminance placement. Typologies in the luminance contrast group relate to the types of glare created by a bright source or task relative to its background. Value contrast was found to be most pervasive, encompassing six typologies related to the light reflectance value of interior materials. The object and luminance placement categories highlight problems related to unpredictable placement of furnishings, signage, and fixtures. It is also likely that there are more typologies than were defined here, however there was insufficient evidence to formally identify those categories.
Conclusion: The four primary factors identified in this study, and their typologies, define the major components of the interior environment that can significantly impact accessibility for the visually impaired user. By providing a better understanding of these typologies, this research may improve a designer’s ability to facilitate access to interior spaces for the growing number of low vision users.
- IES. 2007. ANSI/IES RP-28-07 Lighting and the Visual Environment for Senior Living. IES.
- Passini, Romedi. 1992. Wayfinding in Architecture. 2nd edition. Environmental Design Series v. 4. New York: Van Nostrand Reinhold.
- United States Census Bureau. 2010. “2010 American Community Survey S1810 Disability Characteristics”. U.S. Dept. of Commerce, Office of Economics and Statistics Administration.