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Healthy Interiors for the Visually Impaired

Dak Kopec

Introduction

The United States is home to an aging population, many of whom develop chronic health conditions that impede their ability to live on their own. The 2008 United States (US) Census Bureau projections stated that approximately 22% of the nation's population would be over 65 years of age by the year 2050. The last of the baby boomers, born from 1946 to 1964, will reach the age of 85 by the year 2050 (US Census Bureau 2008), thereby increasing the percentage of older Americans by 125% from the year 1900. Rather than place an older family member into an assisted living facility, many have opted to care for the older person. Termed “informal caregivers,” family members of the aged population currently provide 75–80% of all long-term care in the US (Wright 2005).

William Glasser states that behavior is a result of a person's fears and desires at a given point in time. Control, for the older person, is the fear of freedoms lost and the desire to retain past freedoms (Glasser 1985). These fears and desires become omnipresent as the individual encounters activities of daily living (ADL) that have become more difficult or impossible. For the older person, the loss of control can then lead to a condition called “learned helplessness.” The fundamental idea behind learned helplessness is that motivation becomes diminished as attempts to control one's surroundings are met with futility. The goal for design then is to facilitate autonomy-supportive environments that maximize the older person's freedom to negotiate his or her environment with a high degree of success and safety.

To keep older family members safe and to provide regular assistance as needed, many families have opted to construct a “granny flat.” The term granny flat is not new to the English vernacular; it is at the core of a long tradition where housing multiple generations and extended families in a single home or on a parcel of land was the norm (El Nasser 2004). Unfortunately, once the American suburb gained in popularity, the granny flat lost its appeal and many cities banned them (El Nasser 2004; Jarmusch 2005). Today in the US, we know granny flats by the name “guest suites or houses” in more affluent communities, “in-law suites” in middle-class communities, and by the term “accessory unit” in the newer master-planned communities (El Nasser 2004; Wedner 2008). The granny flat can take the form of a free-standing dwelling that shares a parcel of land with a primary existing structure, or the re-segmenting of an existing home. For many, this is an important housing option for the growing number of aging adults who would rather forgo senior- or assisted-living facilities (El Nasser 2004; Miller 1994; Wedner 2008).

Granny flats, however, are unique environments because they must be designed and constructed to accommodate age-related disabilities and promote independent living. Independent living includes the ability for the occupant to control his or her environment as well as actively ensure his or her safety and well-being. While there are universal guidelines related to universal design and aging-in-place that benefit an older population, the granny flat is often pursued (constructed or renovated) for a specific person with a specific condition. Designers of these environments must become knowledgeable about that person and his or her physical and psychological strengths and limitations when occupying an environment; recall, the goal is to maximize individual control. For example, let's consider the following situation:

Bula is an 83-year-old Caucasian woman who was diagnosed with macular degeneration. She had surgery to correct the problem but ended up with a condition called unilateral mydriasis. Because Bula's health was steadily declining, her family opted to pursue “parasitic architecture” and construct a granny flat onto their existing home. Bula was in her new home for less than a month when she fell and fractured numerous bones in her face. When recovering in the hospital she indicated that she experienced eyestrain and frequent headaches.

Given this situation, it would be logical to conduct a post-occupancy evaluation (POE) to determine what, if anything, could be done to prevent future falls – and how the environment could be modified to reduce eyestrain and headaches.

A POE is a form of research intended to assess an environment's efficacy in meeting its occupant's needs and allow him or her to freely perform ADLs within an autonomy-supportive environment. In order to adequately perform a POE on an environment for a person or group of individuals with a health condition, the evaluator must know about the occupants and their respective health conditions and symptom manifestations. This is a systemic process that necessitates an:

  • Understanding of the problem
  • Understanding of the condition along with symptom manifestation
  • Understanding of the client
  • Understanding of the existing environment and
  • Understanding of how design can affect the environment

Understanding the Problem

We experience the world through an aggregation of information obtained through our combined five senses. It is through these sensory abilities that we have been able to thwart danger and thrive as a species. Among the most important sensory abilities for all primates is vision. Nearly one-third of our brain is dedicated to this sense, and the physical structure of the human eye is among the most complicated in the animal kingdom. However, optimal performance of human vision is dependent upon the provision of light. The iris, which is one of three sphincter muscles in the body, contracts and dilates to control the amount of light entering the eye. When light passes through the pupil it proceeds to the retina, which contains rods and cones. Rods allow us to see in low lighting levels, and cones allow us to see in color and to detect detail. The central area of the retina is called the macula and it contains a high concentration of cones. It's this area that allows us to perceive sharp and detailed images.

Recent estimates from the National Eye Institute indicate that almost 14 million Americans suffer from visual impairments (National Eye Institute 2010). These impairments can be congenital, result from damage or injury to the eye or brain, or occur as part of the natural aging process. In many respects the gradual loss of vision is discounted and simply regarded as normal. However, current population forecasts suggest that by 2050 the United States will be home to 88 million people aged 65 and older. Fifty percent of this population will be living alone, 26% will be living with a spouse, 22% will be living with family members and 2% are expected to be living with non-family members (US Census Bureau 2008). Given that the Americans with Disabilities Act (ADA) protects age-related disabilities, including the decline of vision, the burden of knowledge pertaining to these disabilities and proficient implementation of accommodation strategies for equal accessibility is the responsibility of those who design the built environment (Kopec 2006).

Common visual impairments, other than blindness, include difficulties with depth perception, reduced visual field, sensitivity to glare, and difficulties adjusting from dark to light (Kopec 2007). With age, the lenses of our eyes become less flexible, thereby causing us to experience difficulties focusing when shifting our attention from a distant vista to one that is near. Similarly, as the lenses thicken they take on a yellowish hue from the build up of carotene. This means that older people will experience difficulties distinguishing between blues, purples, and greens (Tilly and Henry Dreyfuss Associates 2002). To accommodate the older person's decline in vision, experts have recommended an increase in lighting levels by 20% while simultaneously bringing about color contrast. (Tilly and Henry Dreyfuss Associates 2002).

When developing designs for people with visual impairments the goal is to compose designs that will maximize a person's ability to perform all of the tasks that he or she desires. The level of one's perceived mastery, or control, over the environment will directly affect belief in one's abilities. Recall that repeated failed attempts at a task will lead a person to develop learned helplessness – and to omit that task within their daily routines. For example, during the interview with Bula she said:

“I used to curl my hair every morning with a curling iron. After the eye surgery, I would sometimes get dizzy when I looked in the bathroom mirror to curl it. See this mark? [she points to a burn scar on her wrist] This is where I burnt myself with the curling iron because I thought I was falling and went to grab the counter top. The hot curling iron fell and burnt my arm. I'm lucky there wasn't any water in the sink because that is where the iron fell. After that I said to myself, enough of this and threw the curling iron away.”

As a result of this incident, Bula doesn't curl her hair anymore because she is afraid she may experience dizziness and fall, and she's afraid that she might burn herself again.

Because morning or evening ablutions are ritualistic, we tend to perform them without thought. Hence, accommodating ideas such as the addition of a vanity table and chair where one can sit while applying make-up or curling their hair may be overlooked. For Bula, who now hates her straight hair, the loss of her ability to control it through curling is another example of something age has taken away from her. Yes, Bula could have someone else curl her hair, she could get a perm, etc., but the point is that Bula wanted to curl it herself and believes she no longer can. This is the premise of learned helplessness. If the environment had been designed to include the vanity table from the time Bula had moved into the space, sitting at the table to curl her hair might have been incorporated into her ritual. Then, when she experienced the dizziness, she would have been sitting and a different outcome may have occurred.

As designers of the built environment, it is important that we don't over-generalize visual impairments as a singular condition with only one perceptual manifestation. Likewise, we need to concede that we have two eyes and as part of the normal aging process each eye may not age in the same way (i.e., a condition may affect vision in only one eye). Because of the multitude of conditions that result in visual impairments, and the variety of perceptual manifestations, the designer must first understand the condition and how it affects the individual's visual understanding of a space. The first step is for the designer to review what is known about vision and its processes through an exploration of the literature. From these baseline data, interviews with individuals who suffer from the condition can be performed to gain greater insights into and understanding of unique variations. This information will help the designer to identify unique conditions and situations pertaining to the environment in question and thereby begin to develop the most appropriate design.

Understanding the Condition

Visual Processing

Vision is a process that requires a series of mechanical movements within the eyeball followed by a series of cognitive interpretations that take place in the visual processing centers of the brain (Kopec 2008). This means that a visual impairment may manifest from a physical deficit or from a cognitive misinterpretation. Understanding the difference will determine the most appropriate design initiatives. A physical deficit might result in changes to lighting or contrast. A cognitive deficit may require the omission of patterns and specific color combinations within certain instances.

The physical eye is much like a balloon filled with water. The fluid within the eye is called vitreous fluid, which has a thicker consistency than water. The center black portion of the eye is called the pupil. This is where images first enter the eye. The colored ring around the pupil is called the iris and it controls how much light enters the eye. The iris is a sphincter muscle that dilates to allow additional light into the eye and contracts to reduce the level of light. With age the sphincter muscle weakens. This means that we can expect a decrease in the effectiveness of the iris to constrict – allowing too much light to enter the eye in some situations.

Once light has entered the eye it is converted into electrical impulses by rods, cones, and ganglion cells. Cones are responsible for depth perception, color, and intensity of light. The rods are extremely sensitive to light and enable us to see at night by signaling the iris to either constrict or dilate. In conditions where the rods are damaged or lost, such as with macular degeneration, the message to constrict the pupil may be lost. This results in mydriasis – when one or both irises fail to constrict. The result is over-exposure to light, subsequently causing periodic episodes of momentary blindness (Kanski 2007; Schwartz 2004). One study showed that patients with photoreceptor rod dysfunction had lower pupil responses, thereby further supporting the connection between light, rod function and pupil diameter (Kawasaki, Anderson, and Kardon 2008). The ganglion cells are used with mesopic vision (low contrast conditions such as at dawn and dusk) and unconscious sight (Kanski 2007), a phenomenon in which the brain registers an object, but the person does not cognitively focus on that object. In low contrast environments, an elderly person with a visual impairment may register an object at an unconscious level, but not respond to it (Shepherd 1994).

In Bula's situation damage to the cones resulted in a permanently dilated pupil which affects the level of light detected by her eyes' cones. This, in turn, affects her depth perception and visual detection of color contrast. High levels of light on the cones also decrease perception of contrast, thus increasing the possibility of unconscious sight, which increases the probability of an accident.

When the physical eye is damaged or impaired, the way in which the person sees the built environment differs from when they have a fully functional eye, and from condition to condition. For example, wet macular degeneration will result in a varying number and size of black spots, while dry macular degeneration will result in a blurring of the center portion of the visual field. Glaucoma, on the other hand, will result in a clouding of vision, with some areas more opaque than others.

Another way in which vision can be impaired is through the malfunctioning of the neural connections within the various visual-processing centers in the brain. These impairments can range from temporal delays in which the world appears as if one were perpetually in a dark room with a strobe light, to dilutions or hallucinations in which the individual merges visual input with ideas or concepts formed within the brain. A third condition is when there has been damage to the brain resulting in a person not being able to see despite a fully functioning eye.

Clearly, these visual impairments require more forethought and understanding of the related conditions that influence visual perception. When a designer understands the condition and how that condition affects sight, he or she can design better living spaces that facilitate a high degree of control for individuals who may suffer from these impairments.

Lighting

We are able to see and interpret the world around us because of natural and artificial light. Natural light has long been seen as advantageous and has been a fundamental tenet of the sustainable design movement since the 1970s (Cohen 2005). There are some environments such as nightclubs, restaurants, and theaters where the value of natural lighting has been overstated (Baker and Steemers 2002). This means that designers must remain judicious in the application of natural and artificial lighting, and ensure such applications are appropriate to the population constituency and corresponding environment.

While it is difficult to mimic the full spectrum of natural lighting – albeit full-spectrum fluorescent lighting does come close (Hathaway, Hargreaves, Thompson, and Novitsky 1992) – the benefits of natural lighting to humans are well established. Natural light helps with vitamin D synthesis, reduces dental caries, enhances visual detection and discernment, and keeps levels of billirubin low – a brownish yellow substance produced when the liver breaks down old red blood cells (Hathaway et al. 1992). Other benefits associated with natural lighting include elevated mood, better balance of circadian rhythms, and increased energy (Boyce 1981). Notwithstanding these benefits, we must concede that some visual deficits may be exacerbated with too much light or lighting orientation and creative mitigation may be necessary.

Understanding the effects of lighting on visual perception of an illuminated environment requires special attention from the designer, particularly when designing for an aging population. For example, washing an interior environment with excessive daylight can actually decrease visual sharpness and increase visual fatigue through the introduction of glare. Contemporary studies show that excessive light causes great discomfort and cognitive impairment to people with age-related macular degeneration or other similar forms of ocular motor deficits (Cheong, Legge, Lawrence, et al. 2007). This discomfort and cognitive impairment may lead individuals to conclude that they cannot control certain factors that contribute to their safety, thus causing them to alter their behaviors. In such cases steps must be taken to guard against high levels of direct light and to avoid applying general rules to unique situations, thus overstating a theory or concept (Baker and Steemers 2002).

Similarly, material selection and uses must be understood in relation to the use of natural lighting (Van Kesteren, Stappers, and de Bruijn 2007). Floor and wall coverings, other surface finishings, along with personal artwork and other items of display, all have a direct relationship with lighting and light performance within the built environment. With regard to individual occupants, the use of, or means by which, natural lighting is facilitated must be tempered with the occupant's unique conditions. For example, high windows are likely to encourage an occupant to stand on a chair or climb a ladder to clean the windows, and people with certain visual problems may have difficulty filtering out excess light.

Understanding the Client

Interview Preparation

Interviewing is a research method used in social science to gain information from an individual's unique perspective. When this interview is conducted prior to an examination and intervention, it is commonly called a needs assessment. Designers can use a needs assessment as part of the pre-design research or POE. To prepare for an interview, designers should craft questions intended to gain greater insights into:

By crafting three to four questions per topic area the most in-depth and accurate information can be obtained. However, care should be taken in the interview process because the person who is being interviewed may interpret a question differently than what was intended. For example, the occupant often performs rituals without much thought. Hence, many rituals may not be revealed without proper questions aimed at extracting that information.

Observation is another important component of the interview process. A designer must be observant of the nuances of the occupant. For example, the occupant may slouch in a chair, may put on and take off eyeglasses, or may continually place items in specific areas (on the coffee table, end table, on adjacent furnishings, or on their lap). If there is a pet in the environment, notice should be taken of where the pet is (in the same room, by the person's feet, on the person's lap, etc.). Observations such as these provide the basis for additional impromptu questions, which can be asked during the interview to gain a more thorough understanding of the occupant's needs.

In many situations a pre-design and POE interview will involve more than one person. If the purpose of the interview is for a child or elderly parent, another family member may be present. Likewise, adults tend to ask for their significant other to be present during an interview. These additional perspectives can be of great value in the creation of a final living environment; however, caution should be exercised not to allow the additional person to dominate the responses. Oftentimes the subject occupant with a health-related concern will be more timid during an interview. In such cases it may be necessary to conduct two interviews, one with the family member as an active participant and one where he or she only observes.

Ideally the interview will be videorecorded for later viewing and in-depth analysis, but if this is not possible an audio recording will suffice. Occupant verbal authorization and acceptance of being recorded is essential. Recording the interview allows a designer to listen to the dialogue as a third party at a later time. It is important to understand that while the interview is taking place the designer is an active participant. This means that critical physical or verbal clues may be overlooked during the interview process itself. By watching or listening at a later time, the designer then becomes an observer and is able to more keenly understand and interpret the information provided during the interview.

The Subject Client

Depending upon the building typology, a designer may have to consider the unique needs of a single person or the aggregate needs of a group with one or more common denominators. Bula's family sought out design assistance in response to a recent accident that they blamed on macular degeneration. By studying Bula during the interview it was clear that she suffered from a visual impairment called unilateral mydriasis.

Mydriasis is a condition characterized by prolonged abnormal dilatation of the iris causing the pupil to appear large. Unilateral means that only one eye is affected. Noticing the differences between Bula's pupils prompted the question of how she acquired this condition. Bula developed unilateral mydriasis as a result of corrective surgery for macular degeneration. A review of the literature revealed that mydriasis often leads to headaches and blurred vision (Hallett and Cogan 1970). Many people with this condition experience light sensitivity and are significantly affected by glare, which often leads to various halo effects (Ritschel, Ihrke, Frisvad, et al. 2009). The manifestation of a halo effect results in a false image appearing around a brightly illuminated object (Schwartz 2004).

Because Bula experienced mydriasis in only one eye, her visual impairment was compounded by the conflicting signals derived from each eye responding differently to lighting levels. During bright conditions one set of visual information came from the fully functional eye that constricted, limiting the amount of light into the pupil, while another set of visual information came from the eye that was permanently dilated, allowing excessive levels of light into the eye (Toy, Simpson, Pleitez, Rosenfield, and Tintner 2008). The brain therefore receives two similar but different sets of visual signals. This is analogous to the phenomenon known as “flicker vertigo” whereby the visual processing centers within the brain receive an imbalance in activity (Brandt 1999; Moore and Harris 2006; Rash 2004).

The high levels of light entering the one eye would thus affect the degree of contrast detected between various elements and colors contained within the environment. It also influences the detection and processing of specular reflections (mirror-like reflection of light from a surface object) and retro-reflections (a reflection of light that creates a glow). Depending on the elements within the environment, the effect can be similar to a fun house that uses an assortment of reflective devices. This is because reflections often influence peripheral vision, which has a slower processing speed (Cheong et al. 2007), prompting a Thorndike halo effect. This halo effect results from a cognitive bias that causes the visual perception of a current object to be influenced by the perception of a former object in a sequence of interpretations (Schwartz 2004). The inconsistent visual processing caused by incongruent visual detection along with specular and retro-reflections and halo effects would likely lead to multiple cognitive misinterpretations causing dizziness and bumping into, or tripping over, various environmental elements.

Not surprisingly, the interview revealed that Bula had routine occurrences of headaches, eye fatigue, difficulties detecting edges, and periodic vertigo. On the end table next to where Bula sat was a pair of prescription sunglasses. She said that she often wore them inside because they helped her with the headaches. Interestingly, Bula seemed embarrassed to reveal that she wore sunglasses inside of her home. This nuance was important because it goes to the development of learned helplessness. Bula believed she had no control over the conditions in her environment except to wear sunglasses inside. However, she was embarrassed by this action. As a result, she altered her daily routine of reading and started to listen to television (she could close her eyes), and she limited her movements within the home because she was afraid of injury. In the US over one-third of adults aged 65 and older fall each year (Hornbrook, Stevens, Wingfield, et al. 1994; Hausdorff, Rios, and Edelber 2001), and in 2005, 15,800 people aged 65 and older died from injuries related to accidental falls, with approximately 1.8 million treated in emergency departments (CDC 2008). Given these numbers and Bula's recent fall, her fear of falling again in the future is understandable.

When a person feels as though he or she has lost control over one or more of his or her freedoms, they will attempt to reassert control, which can lead to dangerous conditions or situations. Bula started to wear sunglasses inside of her home, and whenever possible she spent more time in her daughter and son-in-law's living room, which has a northern orientation making that room darker than her space. Bula wasn't able to articulate why she had adopted these two new behavioral patterns, she just knew that they brought her greater comfort.

Summary

Understanding the client, and having a solid foundation of vision, visual conditions, and aging, revealed five issues of concern that pertained to Bula's environment. These issues are as follows:

  • Issue 1. As part of the normal aging process the lenses of the eyes take on a yellowish hue thus leading to inaccurate perception of color. Bula routinely wore sunglasses inside of the home. The tinted lenses of the sunglasses would exacerbate color distortion and significantly reduce the detection of contrast. Caution must be exercised to use colors that continue to contrast even when a yellowish hue is cast over the colors.
  • Issue 2. One of Bula's irises is permanently dilated. Since the iris controls the amount of light going into the eye and one iris is not working, environmental luminosity must be controlled manually. Bula's attempt to control light manually can be seen in her desire to wear sunglasses inside of the home during the daytime. Caution must be exercised not to make an environment so bright as to inspire an occupant to engage in compensation measures.
  • Issue 3. Excess light causes color to lose vibrancy. A dilated iris equates to excess light which means vibrancy will need to be increased throughout the space. Similarly, because Bula does wear sunglasses inside, color is further distorted by the tint of the sunglasses. Attention will need to be directed at reducing interior brightness as a means to mitigate the desire to wear sunglasses inside of the home.
  • Issue 4. Because it is only one eye that is compromised and a visual image is composed of information obtained from two eyes, inconsistent information can lead to perceptual errors. Special attention will need to be given to sources that can facilitate perceptual errors such as reflections. Also potential trip hazards and items used for stabilization should be assessed for the potential of injury.
  • Issue 5. The occupant had macular degeneration and now unilateral mydriasis, which means that her peripheral vision was likely compromised. Following from issue 4, special attention will need to be given in the assessment of potential trip hazards as well as reflections.

Understanding the Environment

Site Analysis Preparation

After reviewing the literature pertaining to the condition or circumstance of the occupant it is important to develop a list of variables that will need to be included in a site analysis. These variables come from the review of literature and are augmented by information obtained from the interview.

Significant variables to be considered for those with a visual impairment are the type, level, and source of lighting (artificial or natural) as well as the color and color combinations of lighting. Traditional artificial lighting requires bulbs, which often produce a yellow tinge that can distort contrast and color perception as well as contribute to glare. Recall from the review of literature that as people age the eye's lens thickens and takes on a yellowish hue. The yellowish tinge common to many types of artificial lighting thereby becomes enhanced with the older person because of the yellowing of the eye's lens.

The best artificial lighting sources for those with visual impairments are those that simulate the effects of natural lighting by producing the full spectrum of colors. Natural lighting is much easier on the eyes (Edwards and Torcellini 2002) because the iris is not required to continually constrict and dilate, and natural lighting increases contrast and clarity while reducing glare (Gordon 2003). However, caution should be exercised to evaluate sources and levels of natural lighting within individual environments because the interior environment's use of colors and materials will affect perceptual manifestations within the space. Thus, a designer should place special attention on all reflective surfaces (tile or porcelain, granite and marble, surfaces painted with glossy paint or that contain a smooth plastic veneer, flooring with a polyurethane finish, polished metals, and glass table tops, picture frames, and vases) to avoid specular or retro-reflections. When performing the site analysis a designer should note and document current light sources (artificial or natural) along the originating point and pathway of that light. This information can then be analyzed in relation to the identified and perspective reflective surfaces.

As part of the site analysis attention should be directed to low-contrast or monochromatic colors between two or more elevations. For example, a green pedestal sink placed on a green floor can lead to conflicts in depth perception and boundary delineation. One common issue with depth perception derived from a monochromatic design is a white porcelain commode placed on a white tile floor. The white-on-white can lead to location detection errors (i.e., missing the top of a counter and dropping a cup to floor). Similarly, special attention should be given to elevation changes regardless of height. For example, there may be less than a quarter-inch difference between the abutment of two flooring materials. This minuscule change in elevation is enough to bring about a moment of cognitive confusion, especially when one has just awakened, that could then lead to a fall.

Another variable of concern is the assortment of edges found within the built environment. Right-angled or knife-edges from doors and doorframes, counter and tabletops, and bookcases and other furnishings can pose a significant threat. Because of the distorted spatial awareness that often accompanies visual impairments, people tend to bump into or fall against these edges, often leading to bruising or more severe injuries. Ideally, bull-nosed edging should be used throughout the environment. An example of a tool that one might use when performing a site analysis for the purpose of redesigning a space for a person with a health-related issue can be seen in Figure 19.1. Although this example applied to a specific client (Bula) the categories exemplified are generic (i.e., room location, date, time, weather, and outside temperature).

c19-fig-0001
Figure 19.1    Example of a room assessment tool.

Summary

A site analysis for a client's specific issues will demand special attention. In Bula's situation specific issues that needed to be addressed included:

  • Issue 1. Types of artificial lighting will need to be identified. Bulbs that produce light with a yellowish hue will exacerbate the yellowish hue that is produced from the lens of the eye, thus distorting color.
  • Issue 2. Numerous lighting sources will be needed to maintain a balance of light throughout the environment in order to reduce the need for the iris to continually contract and dilate.
  • Issue 3. Reflections will need to be minimized to limit the number of visual messages required for processing within the brain.
  • Issue 4. Assessment of color uses will need to be analyzed in relation to depth perception and spatial awareness.
  • Issue 5. Safety measures will need to be identified in relation to periodic bouts of vertigo and the mechanisms used for stabilization and support.
  • Issue 6. Distance between “safe areas” (places to safely hold on to something should a person experience dizziness or disorientation) will need to be identified and analyzed.

The Environment

Bula's environment was analyzed from the two aforementioned section summaries with special attention given to the maintenance of personal freedom and control. Her environment consisted of a newly constructed, three-room, 500 square foot, rectangular space attached to a primary structure on the eastern side. The three rooms consisted of a bathroom on the north end, a bedroom in the middle, and a combined living/dining/kitchen area on the south end. The environmental assessment was focused on three primary areas of concern. The first was Bula's sensitivity to light, the second was an abundance of glare in relation to direct and ambient lighting levels, and the third was degree of color contrast.

Using the tool illustrated in Figure 19.1, each of the three interior spaces was assessed individually and then as an aggregate whole. The tool provided basic information related to window and door placements, natural lighting levels, as well as light permeation from one room to another. For example:

The tool also allowed for identification of environmental attributes that would contribute to illumination levels. These included the use of color, surface materials, and artifacts contained within the environment. For example:

The environment's high luminance in conjunction with the overuse of the color white, and numerous reflective objects generated numerous hazards for Bula. Stellman notes that reflections can lead to periodic episodes of vertigo and moments of disorientation (Stellman 1998). In Bula's case, the environment likely compromised her lateral inhibitions. In essence, the eye and brain have special mechanisms for seeing edges clearly. These mechanisms allow the eye to see sharp boundaries between objects (e.g., a person standing against a building) and the background (Nabet and Pinter 1991).

Generally, concerns associated with lateral inhibition are the accidental creation of optical illusions. For Bula, who had a visual deficit, there were insufficient visual clues needed to stimulate these cells and thus Bula experienced difficulty identifying boundaries between objects and the background, or walls that protruded. In essence, the environment's high levels of lighting negatively combined with low levels of contrast interfered with Bula's body awareness in relation to objects and features contained within her environment (Wazen and Mitchell 2004). It is this combination of environmental factors that likely led to her initial fall and subsequent learned helplessness behaviors.

Understanding Environmental Design

The combined knowledge gained from the review of literature, interview, and site analysis allows the designer to better understand and address environmental attributes that are contrary to a healthy and empowering environment for people with specific visual impairments. The objective is to gain a comprehensive understanding of the joint nature of the occupant's condition and his or her environment. From the analysis comes the identification and prioritization of actions related to design modification and retrofits. Different people prioritize differently, and some might generate a list based on the prevention of future falls. Another professional might prioritize according to cost and overall budget concerns. Some might even prioritize according to initiatives that can be implemented without hiring a third party. When designing healthy environments, prioritization must be done according to optimal physical and psychological health.

Bula's physical health was compromised by excess light. She complained of headaches, eye strain, and periodic episodes of dizziness. These are all physical health issues that likely contributed to a recent fall requiring hospitalization. On some level, Bula concluded that she could not control her environment, which meant that she could not control nor be proactive with regard to personal safety. The result was an alteration in behaviors and she began to engage in learned helplessness.

A superficial analysis might conclude that the first priority for Bula's environment should be a reduction in lighting levels. However, through a deeper understanding of design principles we know that levels of interior illumination may not be a result of lighting per se. More likely, they are a result of the high reflectivity commonly associated with white and other light colors. Also, natural lighting has many beneficial qualities that we do not want sacrificed too quickly. Before reducing the lighting levels, the priorities should be remediation of elements that enhance luminosity such as color and reflections.

Given Bula's visual deficit and her interior environment the first priority for environmental modification should be the introduction of highly saturated and contrasting colors, particularly between the wall and floor abutment. One area in Bula's environment where color and color contrast should be addressed as soon as possible is the shower stall. High-gloss reflective white ceramic tile walls coupled with a matching built-in bench, also composed of white ceramic tile, and a 4″ ledge that must be traversed while entering and exiting the shower increase the potential of perceptual errors thus risking an accident. Ideally the shower stall should be reconstructed with rough-cut stone and designed with a slight slope to the floor, thereby eliminating the need for a ledge. The bench seat should be redesigned so that the seating area uses a rough-finish material that contrasts with the walls and flooring for easy visibility. Finally, the stall should be fitted with appropriately placed and anchored grab bars.

The second priority should be the reduction of reflective surfaces. This would include using matt-finish paint on the living/dining/kitchen area walls, or using non-reflective wallpaper. This priority should also entail etching all of the clear glass tabletops so that they appear frosted as well as changing the glass in all of the framed artwork to non-glare glass. The mirrored closet doors in the bedroom should be replaced with opaque doors, preferably made from wood. Kitchen and bathroom hardware should be changed from polished to brushed stainless steel, and the bathroom floors and counter tops that have polished ceramic tile should be replaced with rough-cut stone.

The third prioritization should be the reduction of illumination and the balancing of light. One method could be the use of interior window treatments to block out excess light during the brightest times of the day. Other methods might be the use of exterior awnings or a similar shading device to limit levels of direct lighting, the use of window tinting to reflect direct sunlight, or, as a last option, interior window films that diminish the quantity of natural light entering the environment.

Levels of color contrast, reflections, and lighting are all elements that can exacerbate vertigo, but vertigo itself can present irrespective of these elements – albeit, with less frequency and severity. This means that non-reflective grab bars should be strategically placed and incorporated into the overall design scheme for enhanced safety. Also, recessed lighting with compact fluorescent light bulbs that emit a white light should be installed throughout the environment to help even out lighting levels, as well as incorporating task lighting for areas requiring greater visual acuity. Other accommodations should be made, such as the provision of a grooming table located in either the bathroom or bedroom, the use of lighting and electrical face plates that contrast with the wall, and comforter, pillows, and seat cushion covers that are composed of more saturated colors.

Discussion

This environmental analysis was performed on an environment for an elderly woman whom we called Bula. Bula suffers from unilateral mydriasis and experienced a fall within her environment that required hospitalization. Bula's condition, combined with her fall, facilitated the belief that she has limited personal control within her environment. This caused her to alter her behaviors because she feared for her safety. Bula's family recognized the importance of providing care outside of an institutional environment. What they did not know was that older people respond better to autonomy-supportive environments because they are able to retain a high degree of control over their environment and their person. Lost freedoms and abilities symbolize the loss of an active role in our destinies, and behaviors begin to be modified as the person engages in learned helplessness.

What this analysis demonstrates is that whether it is an accessory dwelling for an older family member or an institution, the environment itself can enhance or impede one's sense of control and subsequent behaviors. If the environment is poorly designed the individual may not be able to function effectively within it – thus diminishing his or her sense of control. Once a person no longer believes that he or she has control, learned helplessness will set in and lead to an alteration of behaviors. In Bula's case, she stopped reading because she was experiencing eyestrain, she sat more often because she was afraid of falling, and she wore sunglasses inside of the home. These behavioral changes arose from environmental factors related to high levels of illumination, low levels of contrast, and high levels of reflectivity within the environment.

The family was given a priority list of design initiatives. This list was based on the joint nature of Bula's condition combined with the environmental design. The first priority was to introduce saturated colors as a means of diffusing light intensity. Priority two was the elimination of reflections to reduce the rebounding of light and false images that can induce confusion. Lighting levels, which may seem like the obvious first priority, was listed third because lighting, natural in particular, has many beneficial qualities. However, given the choice between lack of real or perceived control and subsequent learned behaviors in response to lighting levels, perceived control and subsequent behavioral responses must be placed first.

Key Terms

In order to promote a clear understanding of the terms used in this essay, definitions of several key terms are provided below:

  1. Congenital    A condition that has been present since birth.
  2. Activities of daily living (ADL)    All of the activities that person would like to do throughout the course of a day.
  3. Americans with Disabilities Act (ADA)    A law that was enacted by the US Congress in 1990 to guarantee those with disabilities equal access to the built environment.
  4. Autonomy-supportive environment    The ability to perform activities of daily living within an environment.
  5. Cognitive misinterpretation    Conflict between what is present in the world and what the brain perceives as real.
  6. Cones    Responsible for depth perception, color, and intensity of light.
  7. Flicker vertigo    When the visual processing centers within the brain receive an imbalance in activity from two similar but different sets of visual signals.
  8. Ganglion cells    Transmit signals of light and color to the brain for interpretation.
  9. Halo effect    A false image appearing around a brightly illuminated object.
  10. Lateral inhibitions    Mechanisms within the eye and brain that allow us see edges clearly.
  11. Learned helplessness    A condition that occurs as a result of a person experiencing a negative outcome after repeated attempts.
  12. Needs assessment    An assessment of user needs prior to a design concept.
  13. Ocular motor deficit    Faulty component or multiple components found within the eye.
  14. Parasitic architecture    The attachment of a new structure to an older pre-existing structure.
  15. Physical deficit    A disability that results from a faulty organ or organ system.
  16. Post-occupancy evaluation (POE)    An evaluation performed on an environment after the intended occupant has assumed occupancy.
  17. Retro-reflections    A reflection of light that creates a glow.
  18. Rods    Sensitive to light and enable us to see at night by signaling the iris to either constrict or dilate.
  19. Specular reflections    A mirror-like reflection of light from a surface object.
  20. Sphincter muscle    A circular muscle that constricts and dilates to control the passage of light, or solid/liquid substances.
  21. Temporal delay    When the brain processes.
  22. Thorndike halo effect    A cognitive bias that causes the visual perception of a current object to be influenced by the perception of a former object in a sequence of interpretations.
  23. Unilateral mydriasis    When one iris is permanently dilated.

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