Universal Access in the Information Society
https://doi.org/10.1007/s10209-021-00857-5

LONG PAPER

Tailoring assistive smart glasses according to pathologies of visually
impaired individuals: an exploratory investigation on social needs
and difficulties experienced by visually impaired individuals
Simon Ruffieux1· Chiwoong Hwang1 · Vincent Junod2 · Roberto Caldara3 · Denis Lalanne1 · Nicolas Ruffieux4

Accepted: 29 November 2021
© The Author(s) 2021

Abstract
Recent advances in the field of assistive devices technology represent a great opportunity for improving the quality of life ofpeople with moderate to severe visual impairment. However, it is still unclear what are the precise daily difficulties, needs
and expectations of the smart glasses technology for visually impaired individuals. To this aim, we conducted a survey basedon three questionnaires to provide qualitative and quantitative insights on those questions across five groups suffering fromvarious visual pathologies ( N = 50 ). The results clearly showed the importance of developing tailored solutions to fulfill
the heterogeneous daily difficulties and needs identified across pathologies. Overall, groups shared similar expectations
regarding the assistive smart glasses functionalities in order to improve social interactions.
Keywords Accessibility · Visual impairment · Assistive devices · Smart glasses · Social study · Expectations

1 Introduction* Simon Ruffieux
simon.ruffieux@unifr.ch
Chiwoong Hwang
chiwoong.hwang@unifr.ch
Vincent Junod
vincent.junod@chuv.ch
Roberto Caldara
roberto.caldara@unifr.ch
Denis Lalanne
denis.lalanne@unifr.ch
Nicolas Ruffieux
nicolas.ruffieux@unifr.ch1

Human‑IST Institute, Department of Computer Science,
University of Fribourg, Fribourg, Switzerland

2

Department of Psychiatry, Lausanne University Hospital,
Lausanne, Switzerland

3

Eye and Brain Mapping Laboratory, Departmentof Psychology, University of Fribourg, Fribourg, Switzerland

4

Department of Special Education, University of Fribourg,
Fribourg, Switzerland

There are about 36 million blind people and 216 million
people with moderate to severe visual impairment in theworld [4], a population also referred to as individuals withlow vision. According to the World Health Organization,
low vision is currently defined as individuals with visualacuity below 6/18 down to and including 3/60 in the better
eye with best correction [24]. This number of individuals
affected is expected to increase with population ageing, as
the majority of people with vision impairment are over theage of 50 years. A large range of heterogeneous pathologies
can be aggregated in this definition and each pathology usually exhibits different types of symptoms and may therefore
require different functionalities from assistive devices.
Numerous technological assistive devices have alreadybeen developed in research projects or are available commercially, such as smart white canes, reading devices, textto-speech, dedicated smartphone applications and mobility
aids. Most of these tools focus on assisting visually impaired
people (VIs) in their daily life functions. However, only few
solutions focus on facilitating social interactions, which isone of the main handicaps and complaints of VIs as shownin this study. Key elements for social interaction such as face
identification, visual attention awareness and facial expressions of emotion processing represent major challenges for

13Vol.:(0123456789)

Universal Access in the Information Society

VIs. To our knowledge, there is currently no clinically validated solution aiming specifically at these social functions.
Therefore, our research group is currently developing andclinically assessing the use of smart glasses and augmented
reality to assist VIs with social interactions.
Very few studies have actually investigated the concreteneeds of VIs from smart glasses assistive technologies.
These studies have been performed with limited quantity ofparticipants and using open interviews or custom questionnaires not made publicly available [28, 29]. To our knowledge, no study has yet investigated difficulties and needs of
VIs while considering the different types of deficit withinpeople with low-vision. This gap in the literature is significant, as we believe defining and understanding concretely
the range of needs and expectations of people with lowvision according to their pathology and symptoms is critical
for researchers and developers in order to design tailoreduser-centered solutions.
In this study, we investigate the link between the qualityof life of 50 visually impaired individuals and their typeof visual deficit, their difficulties in functional and social
interaction as well as their expectations for smart glasses
as assistive multipurpose tools. Three questionnaires havebeen used for this investigation. The NEI-VFQ-25 is a standard questionnaire that has been largely used to assesses thegeneral quality of life of VIs [23]. In order to better quantify
specific difficulties and expectations, we also developed two
new questionnaires in collaboration with psychologists andthe Swiss Association of the Blind and Visually Impaired(SBV). The DRFE questionnaire assesses specific strategies and difficulties in recognizing faces, emotions andvisual attention and the ESGAD assesses the currently usedassistive technologies and the expectations regarding smart
glasses as an assistive device. We notably hypothesize thatVIs have different needs and expectations from assistive
technologies depending on their specific pathology andsymptoms. With this study, we aim at better characterizingthese specific needs in order to guide future works on assistive tools for VIs.

2 State‑of‑the‑art
The majority of assistive devices developed for visually
impaired people have been focusing on supporting functional tasks such as reading, navigation and obstacle avoidance as highlighted by the survey of Tapu et al. [35]. Many
prototypes have been developed in the context of academia
and research, most of them relying on technical approaches,
trying to leverage the potential of new technologies without
relying on a proper user-centered design methodology [13,14, 18, 38]. Commercial products that have attracted the VI

13community, such as OrCam1 or eSight2, also mostly concentrated on challenges in this area.
In their comprehensive survey, Bhowmick and Hazarika
implied that researchers should pay more attention to social
aspects of assistive devices [3]. Meanwhile, although novel
types of assistive devices were introduced with technologicaladvancement in the last decades, only a few of them havebeen accepted by users. Krishna et al. highlighted the lackof user-centered design [20], while Gori et al. reported that
obtrusiveness of device along with extensive time and efforts
required to learn technologies involved could be the main
reasons hindering user acceptance [15]. Moreover, many ofthe proposed systems did not undergo clinical tests to validate their effectiveness [28]. Nevertheless, technologies are
evolving rapidly and latest computing devices may support
the visually impaired satisfactorily [16].
Smart glasses have received tremendous attention
recently and emerged as a new platform of choice, notably
due to hands-free interaction in contrast to smartphones,
augmented reality (AR) capabilities and constant availability[20]. Besides, studies performed in other domains showedthat smart glasses have great potential to enhance social
interaction [21, 37]. Typically, assistive systems apply two
different concepts to transfer information to users: sensory
substitution and visual augmentation. Sensory substitution(vision substitution) is a coping strategy for visual impairment that converts visual input to auditory and/or tactile
stimuli [6, 12, 22, 33]. Visual augmentation (vision enhancement) refers to enhancing vision of visually impaired people, by adding or subtracting information from their fieldof vision [2, 16, 18, 34, 39]. Sensory substitution technique
can be highly effective to support completely blind users,
but visual augmentation may be more advantageous for low
vision [10]. Several researches have adressed assistive technologies for VIs that focus on functional issues in daily life.
For example, Zhao et al. demonstrated that AR can effectively improve mobility (e.g., walking through stairs) for
people with low vision by displaying or projecting digital
figures on physical objects [40]. In their work, Hwang andPeli developed a prototype that reinforces object detection byintensifying edges in images captured through Google Glass[18]. Huang et al. used a Microsoft HoloLens device to help
VIs understand visual signs like door labels [17]. Caraiman
et al. proposed a system that identifies obstacles and delivers auditory or tactile feedback in order to help VIs be moreaware of their surroundings when navigating [6]. Similarly,
Suresh et al. developed a sensory substitution device for VIs
that provided auditory or tactile signals on wearables [33].
Their project, the Smart Glass, could detect objects using
1
2

https://​www.​orcam.​com/.
https://​esigh​teyew​ear.​com/.

Universal Access in the Information Society

deep learning algorithms and estimate distances to themthrough ultrasonic sensors.
Several studies showed that social interaction can be particularly demanding for VIs because communication withothers includes exchanges of nonverbal cues such as gaze,
gesture, or facial expression that cannot be recognized by
VIs [5, 36]. Phillips and Proulx insisted that assistive devices
should facilitate acquisition of nonverbal information; they
defined a set of design criteria in their work: functionality,
usability, cognitive demand and aesthetics [25]. According
to Qiu et al., helping the blind interpret and respond to visualcues from others may lead to more successful communication [27]. Since aging is correlated with visual impairment,
older adults may be especially susceptible to poor social
interaction [9]. In the study of Desrosiers et al., the elderlywith visual impairment showed significantly reduced social
activities compared to others with normal vision [11]. Furthermore, Cimarolli et al. conducted a longitudinal study
with 364 visually impaired elders to discover temporalchanges in their difficulties finding that challenges for social
events (e.g. eating out or recognizing people) persist consistently or become worse in a long term [8]. As previously
mentioned, few studies in the field of assistive technology
have attempted to foster social interaction for VIs. Chaudhry
and Chandra proposed a facial detection and recognition
system to assist visually impaired people [7]. Using a camera from an Android device, their system could distinguishfaces relying on an internal database or online server. The
success rates for facial detection and recognition were 93%
and 70%, respectively. Similarly, Zhao et al. implemented
a smartphone-based prototype, the Accessibility Bot, that
could detect faces of friends on Facebook messenger [41].
It also provided supplementary information about people
around the user including their locations and facial expressions. Although the system was not always easy to use inreal-world settings, it had a positive impact on social interactions of the participants. Sarfraz et al. worked on a wearable
multimodal system to help VIs understand non-verbal cues
via auditory and tactile feedback [31]. They built a prototype
that consisted of a body-worn camera, haptic-belt and boneconduction headset to inform users of the identification andposition as well as visual attention of other people nearby.
The evaluation performed with 12 VI persons demonstrated
the usefulness of the proposed solution; although several
subjects reported the complexity of the wearable system fora daily usage.
More recently, some studies have taken advantages ofsmart glasses to improve social interactions of VIs. Qiu et al.
tried to reinforce the sense of involvement of blind people
when interacting with others by simulating natural gaze [26].
They designed a prototype named Social Glasses that could
display artificial gaze of VIs in response to the normallysighted and it promoted more engaging conversations. In

our previous work, a prototype, based on the Epson Moverio
BT-200 smart glasses, was developed to identify surrounding people and their emotions, the feedback was provided
through sound and visual augmentation [28]. The preliminary evaluation with VIs demonstrated the feasibility of theconcept and the strong interest of VIs for social assistive
smart glasses. The study also highlighted remaining technical and hardware problems that should be resolved before
using such system in the wild and the strong heterogeneityof expectations and needs amongst visually impaired users.
Buimer et al. developed a custom assistive device for VIs
that supports emotional recognition by utilizing haptic technologies [5]. In this project, six emotions captured througha camera on glasses were mapped into the same number ofvibrators on a waist belt so that the user can receive tactile
signals on different spots according to emotional expressions of interlocutors. Even though the authors observed
limitations in differentiating emotions due to luminosity
conditions or changes in angles of faces, more than half of
8 participants with visual impairment in their experiment
could use the system without difficulty during conversations.
Only few studies investigated the concrete needs andexpectations of VIs regarding assistive devices. The impactof the aesthetics of assistive devices has been investigated bySantos et al. [30]. They interviewed eight young individuals
who knew at least one visually impaired person in order toevaluate their perception of disability. Their study concludes
that devices without negative symbolism and with modern
aesthetics such as smart glasses are better accepted and areless stigmatizing than more traditional assistive devices suchas white canes. The work of Shinohara and Wobbrock indicated that VIs tend to avoid being identified as the disabledand stigmatized [32]. In his study, Sandnes attempted tocharacterize needs of VIs through directed interviews andshowed that facial recognition and text reading are reported
as the biggest challenges [29]. In their study, Azenkot et al.
noticed that people with low vision often struggle with navigating or finding products when shopping and suggested thatvisual augmentation with smart glasses can benefit the target
users by exploiting their residual vision [2]. The results fromour prior study revealed that assistive technology for VIs
has to be tailored to specific needs of the end-user [28]. For
example, some may prefer visual feedback from the systembecause of intrusiveness, whereas others feel more secured
when auditory or tactile support is given due to the severity of visual loss. Contextual adaptation of communication
method may also play an important role, and as VIs often
have to rely on hearing for various activities, it may not be
ideal to provide auditory feedback especially in noisy outdoor settings [19, 35].
To the best of our knowledge, there have been limited
studies that systematically analyzed requirements of assistive devices, and more specifically smart glasses, for visually13

Universal Access in the Information Society
Table 1  Distribution of pathologies amongst the studied population
Pathology

Group size

Age-related macular degeneration (AMD)Retinitis pigmentosa (RP)Glaucoma (Gl)
Optical nerve lesion (ONL)
Others

11
14
6
5
14

impaired individuals with an adequate number of welldefined clinical populations.

3 Methodology
The study consisted in an interview with visually impaired
individuals, in which the participants were asked to answer
three different questionnaires in order to assess: (1) quality oflife, (2) daily difficulties, (3) face processing strategies during social interactions and (4) expectations for smart glasses
as an assistive device. The participants of the study haveall been recruited on a voluntary basis through the Swiss
Association for the Blind and Visually Impaired (SBV). The
population consisted of 50 persons, French native speakers,
aged from 28 to 87 years ( M = 61.68, SD = 14.14, ); comprising 37 women and 13 men. The population was classified
into 5 distinct groups according to their visual pathology(Table 1): Age-related macular degeneration (AMD), Retinitis pigmentosa (RP), Glaucoma (Gl), Optical nerve lesion(ONL) and Others. The Others group is comprised of lesscommon pathologies (Ocular toxoplasmosis, Hydrocephalus, Thrombosis, etc.). Typically, the potential visual symptoms vary according to the severity of each pathology; mostcommon visual symptoms are summarized below:– AMD: darkening/loss of central vision, distortion, overall
blurriness and sensitivity to glare;– RP: darkening/loss of peripheral vision, impaired nightvision, loss of contrast sensitivity;– Gl: darkening/loss of peripheral vision, blurriness, sensitivity to glare;– ONL: loss of visual field (central and or peripheral), lossof color vision, flashing light;
As visually impaired individuals present major differences in terms of difficulties and needs, low vision therapists
insist on the importance of tailored rehabilitation and support. This aspect must be considered carefully by researchers aiming at developing smart glasses technology for thispopulation. To our knowledge, there does currently not exist
any specific scale-based questionnaire addressing those

13

questions. Therefore, we collaborated with a study groupconsisting of one certified clinical neuropsychologist andtwo certified low vision therapists from the SBV to identify
the most relevant questions that should be addressed to VIs
in order to have a better understanding on face processing
strategies used during social interactions (DRFE) and on
their expectations towards smart glasses devices (ESGAD).
This resulted in the design of a set of three questionnaires
detailed below. The NEI questionnaire, already largely usedby clinicians internationally [23], provides a standardized
global scale as well as sub-scales for specific topics, while
the two new exploratory questionnaires (DRFE and ESGAD)
provide qualitative information for each addressed item (forwhich the use of a scale is possible only for individual questions). Those questionnaires can be reused freely for research
purposes and are available online3 in French and English:
1. NEI-VFQ 25—A standard questionnaire commonlyused by clinicians to assess quality of life of VIs through25 questions to address 12 sub-scales: general health;general vision; ocular pain; near activities; distanceactivities; vision specific: social functioning, mental
health, role difficulties, dependency; driving; color
vision and peripheral vision [23]. The questionnaire
has been slightly adapted in collaboration with the SBV;
the Driving subscale has notably been replaced by theSensitivity to luminosity subscale. Individual scores arerecoded and transformed on a scale from 0 to 100, where
100 represents the best possible performance and 0 theworst. An average score is calculated for each of the
12 subscales, and an average of the subscales scores iscalculated to obtain the overall composite score.
2. Difficulties in Recognizing Faces and Emotions(DRFE) - An exploratory questionnaire to assess thefunctional origins of social difficulties and their impact
on daily life. It consists of 14 questions, based on the
5-points Likert scale. The questions address the following topics: difficulty to recognize faces for different
familiarity levels; distance at which recognition difficulty starts; negative impact on the person’s daily life;
impact of the luminosity conditions; strategies to copewith deficit in face and emotion recognition and generaldifficulties during social interactions.
3. Expectations on Smart Glasses as Assistive Device(ESGAD) - An exploratory questionnaire to assess theassistive technologies currently used by the Vis and their
expectations regarding smart glasses assistive devices.
The questionnaire consists of 8 questions, based on the
5-points Likert scale, that address the following topics:
functional and social daily difficulties, commonly used3

https://​iknowu.​human-​ist.​ch/​resou​rces

Universal Access in the Information Society
Fig. 1  Results of the whole
population on the NEI questionnaire. The Composite andthe 12 subscales scores arepresented in the graphic as individual boxplots. The NEI Score
represents the evaluation of
the item by the patient (where
100 represents the best possible
score and 0 the worst)

assistive devices, knowledge of smart glasses technologies, expectations from a smart glasses assistive device,desired information returned by the device on recognized persons and finally importance of comfort andaesthetic of the device.
The interviews were performed in SBV offices in Fribourgand Lausanne (Switzerland) in 2018. They followed a strict
procedure, described hereafter. Upon arrival, the participants
were greeted and led to a specific room for the interview. The
goals of the study were briefly introduced to the participants
and they were advised of the confidentiality of the study
and the possibility to opt out at any time. The participants
were asked to fill a consent form. Then, general information
about the participants was collected: age, visual pathology,
study level, profession, actual social situation. The interview
continued with the questionnaires, each question and propositions of answers were read out loud by the interviewer tothe participants. The questionnaires were presented in thefollowing order: NEI-VFQ, DRFE and ESGAD. Note that
the ESGAD questionnaire contains a short text introducing
the concept of smart glasses assistive device for VIs. At theend of the interview, the participant had the chance to ask
questions, add specific remarks and discuss openly with theinterviewer. The procedure lasted approximately 45 minutes
on average.

4 Results
The results for the three questionnaires are presented intheir respective section below. For each questionnaire, themost relevant items are summarized for the general population and for each distinct group. This approach provides thepossibility to highlight the general tendency of the studied
population and the main differences amongst the consideredgroups. The statistics have been computed with the IBM

SPSS Statistics software (Version 25). The results of therelevant items are provided with their Mean and Standard
Deviation (M, SD) or their Median and Interquartile Range(Mdn, IQR) and illustrated with box plot charts or with bar
charts. Nonparametric tests were used to analyze the results
per visual pathology group.

4.1 NEI‑VFQ‑25 questionnaire
The main results of this questionnaire are resumed in Fig. 1.
The reported values from this questionnaire indicate the following information; a score of 0 indicates severe or frequentdifficulties for the considered item, while a score of 100 indicates infrequent or absence of difficulties. The studied population presents a low composite score ( M = 45, SD = 14 ).
Their general health (M = 51, SD = 24) is low comparedto the score of a standard population (M = 69, SD = 24)
reported in a previous study [23]. As expected, our sample
reported difficulties with general vision (M = 37, SD = 17).
Their vision was decomposed into five different characteristics: moderate difficulties with near vision (M = 47, SD =17), frequent problems with distant vision (M = 30, SD =18), some difficulties with peripheral vision with a strong
variance amongst subjects (M = 40, SD = 38), some difficulties with color vision (M = 63, SD = 26) and somedifficulties regarding sensitivity to luminosity (M = 40, SD= 30). Social functioning is generally reported as a moderate difficulty (M = 62, SD = 20). What characterizes theresults is the strong variability of the scores for most subscales. Additional information can be extracted by analyzing
specific items of the questionnaire. The overall population
seems more subject to glare in outdoor conditions (Q5: M =34, SD = 32) compared to indoor conditions (Q6: M = 46,
SD = 34). They have severe difficulties to detect obstacles
on the ground in low (Q13: M = 27, SD = 26) and highluminosity conditions (Q14: M = 29, SD = 20).

13

Universal Access in the Information Society
Fig. 2  Results for vision-related
subscales of the NEI questionnaire presented per visual
pathology

The analysis of the results according to the distinctgroups considered in the study provides additional information. The global composite score is homogeneously low
for all the groups; only the Others group exhibits larger
variations. The AMD and RP groups reported a better general health compared to the other groups. The results forthe vision-related subscales are illustrated in Fig. 2. The
following facts can be observed: the general vision score ishomogeneously low for all groups, with a larger variation
for the Others group. Near vision has been reported as lessproblematic than distance vision by all considered groups.
The ONL population has large variations for distant andnear vision. Peripheral vision exhibits a large variation
between and within groups; as expected RP, Gl and ONLgroups report severe difficulties with peripheral vision,
while AMD population reports only moderate difficulties. Color vision is not reported as problematic by anyof the studied groups. The sensitivity to luminosity is thesubscale presenting the most variations between groups.
The AMD, RP and Gl group have severe difficulties, while
ONL and Others are less impacted.
The analysis of the results per visual pathology group provides interesting information regarding specific questions.
The RP group is significantly more impaired by light outside(Q6: M = 5, SD = 26) than inside (Q5: M = 29, SD = 19), T= 15, z = − 2.07, p = .026 ; the AMD group is significantly
more impaired by glare in indoor conditions (Q5: M = 25,
SD = 19) compared to the rest of the studied population,t(24) = 3.12, p = .005; while on the contrary, the Gl groupis significantly more impaired by glare in outdoor conditions(Q6: M = 8, SD = 13) compared to the rest of the studied
population, t(12) = 3.89, p = .002. The AMD group reports
severe difficulties to read a paragraph in a newspaper (Q7:
M = 0, SD = 0) and to read street signs (Q11: M = 5, SD =10); they report more difficulties on those two items than theother groups, t(15) = 4.86, p < .001. In contrast, individuals
with AMD report less difficulties in seeing elements with13

their peripheral vision than other groups (Q15: M = 61, SD= 36), t(17) = − 2.23, p = .039.

4.2 DRFE questionnaire
The results of this questionnaire highlight the need for social
assistive tools, notably with Face, Emotion and Visual Attention as illustrated in Fig. 3. Difficulties to recognize faces
are reported as being a severe discomfort, while difficulties
with emotions are reported as being a moderate discomfort.
Participants report frequent difficulties with visual attention
awareness in 1-to-1 and group conditions.
Most participants (68%) have difficulties recognizing
faces when they are close (< 1 m) and almost all of them(98%) report difficulties at distance (> 1 m). They reportdifficulties with face recognition as a severe discomfort for
their daily life (Mdn = 4, IQR = 2). This difficulty is present regardless of the familiarity of the person to recognize.
Most participants (68%) report looking directly at the facein order to identify a person, while few (32%) report looking
eccentrically. Most participants (92%) report not focusing
on a specific aspect of a face during the identification process. Low and high luminosity conditions have a negative
impact on the identification process for most participants(88% and 82%, respectively). Participants largely rely on
voice (98%) to identify a person, followed by gait (24%) andclothes (16%). Most participants (80%) report difficulties
to recognize facial expressions of emotion and this holds
true for all types of emotions. However, this difficulty isreported as being only a moderate discomfort (Mdn = 3,
IQR = 2). Participants also report very frequent difficulties in visual attention: knowing if a single interlocutor islooking at them (Mdn = 2, IQR = 2) and knowing if aninterlocutor is addressing them during a group discussion(Mdn = 2, IQR = 1).
The analysis of results per group for selected items ispresented in Fig. 4. All groups report difficulties with face

Universal Access in the Information Society
Fig. 3  Histograms illustrating
the percentage of population
experiencing difficulties in their
daily life for selected items.
Top: discomfort due to difficulty
in recognizing faces and emotions. Bottom: frequency of difficulties with visual attention in
1-to-1 and group conversations

Fig. 4  Selected results of the
DRFE questionnaire presented
per visual pathology. Left:
Reported discomfort withdifficulties with Face Recognition and Emotion Recognition.
Right: Reported frequency ofdifficulties with visual attention
in direct and group communications (“Frequency” scale
was reversed for readability:
1=never, 5=always)

recognition as being a severe discomfort. The ONL group
has more variations for that item; only 50% of ONL reportdifficulty recognizing familiar faces and 80% report difficulties with unfamiliar faces. Other groups do not report differences between familiar and unfamiliar faces. Most groups
report, on average, moderate difficulties with emotion recognition. This difficulty varies largely within groups, from mild
to severe difficulties. All groups report experiencing difficulties with visual attention detection frequently. AMD and
ONL groups seem to exhibit larger variations for those items(from never to always) compared to the other groups. The
analysis of specific questions provides additional insights.
The majority of AMD (82%) and RP (79%) individual reporthaving difficulties recognizing faces even at close distance(<1 meter), while fewer individuals from ONL (60%), Others (57%) or Gl (51%) groups report such difficulties. All
subjects, except a single individual with AMD, reported difficulties to recognize faces at a distance above 1 meter. Most
AMD individuals (91%) report looking eccentrically at faces
during the identification process; only a single individual

13Universal Access in the Information Society
Fig. 5  Expectations on the functionalities that an assistive smart
glasses device should provide.
Items are ordered by preferenceof the whole population and theresults are presented for eachvisual pathology(9%) reported looking directly at the face. On the contrary,most RP individuals (79%) report looking directly at theface, while few (21%) report looking eccentrically.

4.3 ESGAD questionnaire
The results of this questionnaire highlight the daily functional and social difficulties encountered by the considered
population: reading and writing (functional) and face recognition & emotion recognition (social). The main expectations of the distinct groups for assistive smart glasses devices
are presented in Fig. 5. The studied population reports thefollowing difficulties with daily functional tasks: reading(94%), writing (84%), localization of objects (60%), mobility (56%), identification of objects (50%) and meal preparation (30%). The participants report the following difficulties
with daily social tasks: face identification (94%), Emotion
Recognition (70%), other’s empathy (68%), establish contact with others (22%), sports (12%) and cultural activities(10%). Surprisingly, less than a third of the studied population (32%) is aware of the existence of smart glasses andtheir potential as an assistive device for visually impaired
individuals. In their daily life, they currently rely on thefollowing assistive devices: white cane (88%), magnifying
glass (66%), digital screens for reading (42%), guide dog(4%) and trustworthy persons (4%). They report the following expectations concerning the functionalities that would
be useful for them on assistive smart glasses: face recognition (88%), reading (86%), mobility (48%), object localization (32%), emotion recognition (32%), object identification (30%) and GPS functions (28%). Assuming they would
have such device with face recognition functionality, theywould like to obtain the name of a target person (100%)and to distinguish strangers from known people (54%). They
all rejected the idea of having the information about age.
Finally, most participants reported the aesthetic (84%) andthe comfort (100%) as being important factors.

13

As visible in Fig. 5, most groups share the same expectations: Face recognition and Reading. The ONL group reports
fewer daily difficulties than others in general and the only
functionality required by the majority is reading assistance.
Compared to other groups, Object localization and identification seemed to be particularly important for RP group.

5 Discussion
The analysis of the results obtained from the three different
questionnaires provides insights on the general quality oflife, daily difficulties, needs and expectations of the studied populations. The results notably highlight the difficulties with social interactions and the needs for an assistive
technology designed for visually impaired that focuses on
facilitating daily interactions with others. The analysis of
the results of the NEI questionnaire shows that the studied
populations are largely impacted in their quality of life by
the symptoms of their pathology. Their overall score, on
average, is low and the comparison of the subscale scoresobtained in this study with the score obtained for the standard population presented in the original study support thatclaim [23]. This effect might potentially originate from thesample population considered in our study: the participants
were recruited through the SBV association, which often
consists of persons who contact them because they sufferfrom severe symptoms. The analysis also highlights the difficulties experienced daily for social interactions; this item isfrequently reported as a problem and considered as a strong
discomfort by most participants. The specific items related
to face recognition outline the strong impact of distance,
indicating that persons closer to one meter would not always
need to be recognized by the system. The degree of familiarity of a face only plays a minor effect and should not necessarily be taken into considerations (i.e. they have the samedifficulty recognizing the face of a very close-relative orUniversal Access in the Information Society
Table 2  Preferredfunctionalities expected by mostof the population within eachgroup (bold: ≥ 50%, light-grey:≥ 30%)

Face recogni- Reading
tion
AMD
RP
Gl
ONL
Others

1
1
1
2
1

2
2
1
1
2

Mobility

Object localization

4
3
2
3

3
4
2
4

Emotion recog- Object
nitionidentification
3
5

6

5

The numbers represent the order of preference (1 represents the highest priority)

the face of an occasional colleague). The importance andnegative impact of luminosity and contrast are also clearlyhighlighted by the results as key elements to take into consideration; notably in terms of the information provided
through the display of the glasses, similarly to the recent
work performed by Zhao et al. [39].
The analysis of the DRFE questionnaire characterizes thestrong difficulties with daily social interactions for the studied population. The most problematic items are face identification, visual attention in groups and -to a lesser extentemotion recognition. The difficulty to identify faces isreported by almost all participants and types of pathologies
as a strong or very strong discomfort. Only few individualsof the ONL group, presenting lighter visual deficit symptoms, did not report strong discomfort for that item. Almost
all participants (98%) reported difficulties to identify faces
at distances superior to one meter. A majority of participants (68%) reported difficulties at distances inferior to one
meter. Inspecting the results at the pathology level, it appears
that more individuals from AMD and RP groups reported
having difficulties at close range compared to other groups.
This supports the idea that face identification assistance atclose range must be tailored according to each individual’s
preferences. Difficulties with visual attention, i.e. to understand when one or several interlocutors are looking at the VI
individual, are reported as occurring frequently to very frequently for most of the studied population. Such difficulties
can notably be worsened in group conversations where turntaking is often complex and implicitly managed through eye
contacts (mutual-break and mutual-hold). According to theresults, individuals from the AMD and ONL groups are less
impacted by this difficulty. It is interesting to note that visual
attention in live conversations has only been addressed ina few studies and it seems that real expectations from VIs
have not sufficiently been considered leading to prototypes
that were not well accepted by the target population [26].
Understanding facial expressions of emotion was reported asa moderate discomfort on average, however the heterogeneity of the reported discomfort amongst the studied population emphasizes the need to provide the option to tailor thatfunctionality for each individual. Many participants reported

relying on their auditory sense to infer the emotion of theirinterlocutor, which might not always possible in everyday
life situations. Note that the ONL and Others populations
reported very heterogeneous discomfort for that specificitem, showing strong variability even within groups.
The analysis of the ESGAD questionnaire highlights
the fact that expectations for the smart glasses are largely
shared across all groups considered in this study. The resultspresented in Table 2 highlight the different functionalities
expected and their preferred order for each group. The numbers, in bold and in light grey, represent expectations desiredby more than 50% and more than 30%, respectively. All considered pathologies share the same top-2 expectations. Face
recognition was, by far, the most requested functionality,
which clearly indicates that participants need additional aids
to support such daily social function. Reading was the second most desired functionality, which could indicate thatthey may not be fully satisfied with their current text reading
aids. For face recognition, participants reported that theywish to be notified not only about identity of known persons
but also about whether or not that person is known to them; afeature that is often absent in most existing systems. Mobility and object localization/identification functionalities werealso requested by many participants. Surprisingly, althoughmany individuals reported frequent difficulties with visual
attention detection in the DRFE questionnaire, it was not
requested as a desired functionality. This may be explainedby the fact that “Visual attention detection” was not part ofthe proposed items in the ESGAD questionnaire; participants had to mention it explicitly in the “Others” section.
Facial emotion recognition was only requested by 33% of
the population, which is in par with the moderate difficulties
reported for that specific item. Interestingly, the RP groupseems to expect all functionalities, although their composite
and general vision scores were not significantly lower in
the NEI questionnaire. This demonstrates the importanceof the two specific questionnaires developed in this study tobetter assess the real needs and expectations of considered
populations.
Finally, the current study has some limitations thatare resumed below. The information considered for the13

Universal Access in the Information Society

visual acuity was self-reported by the patients; indeed, mostpatients were not aware of their exact medical visual acuity, which did not allow assessing the correlation between
visual acuity and the other factors considered in the study.
The sample population considered was composed of only
few young persons and mostly of female individuals, sharing a common cultural background as all individuals were
living in the french region of Switzerland. These specificities might have impacted the results; the age (M = 61.68,
SD = 14.14) might notably have impacted their knowledge
and attitude towards adopting new technologies, while theshared regional background might have an impact on theirexpressed needs. The limited size of the ONL and Gl groups
and strong heterogeneity of the ONL and Others groups may
have hindered the possibility to obtain additional statistically significant results. For all these considerations, the generalizability of the findings to a worldwide population ofvisually impaired must be taken with caution. It would beinteresting to reproduce the same study in different regionsof the world to reduce the regional impact and increase thesize of the population samples. Furthermore, the current
study could not address several important topics that should
be investigated in future studies; an in-depth analysis of
the preferred feedback channels of the considered populations should notably be further investigated as it represents
a crucial aspect for future developments. The economical
aspect of smart glasses device was not considered, although
it would be interesting to know the acceptable price-range
users would be willing to pay. The privacy issues, in terms of
public acceptance and legal consideration should also be further investigated, notably for specific public contexts such asclassrooms. A recent study already demonstrated that people
tend to be more willing to grant access to their image to help
people with disabilities [1]. Reported as a main drawbackof existing solutions in the literature [35], future developed
solutions should focus on instructions, accessibility and support to assist the users with the initial setup and daily use of
the proposed systems.
As mentioned in the state-of-the-art discussion, mostresearch articles that investigated the needs of visually
impaired individuals in terms of technological assistive
devices focused on specific context such as stigmatization[30, 32] or on specific types of applications such as shopping [2] or mobility [40]. Most of those studies have been
performed through open interviews and/or custom questionnaires with a limited population [29]. Furthermore, considered populations do not represent the whole continuum ofpotential pathologies in visual impairment conditions andthe subjects often consist of persons in the academic world.
In this work, we tried to provide an overview of the generalneeds of visually impaired individuals, while covering several distinct pathologies in order to provide a better understanding of the common and distinct needs and expectations.

13

We used a combination of standard and custom questionnaires in order to provide several different perspectives on
the topic: general health conditions, daily difficulties, dailysocial difficulties and specific questions regarding the potential of smart glasses as an assistive device. Finally, we relied
only on voluntary subjects that are registered to the Swiss
Association for the Blind and Visually Impaired and who
have been interviewed with a well-defined methodology.

6 Summary of findings
We summarize in the following the most important findingsthat could be inferred from this study in order to guide thedevelopment of future augmented reality researches, software and products targeting visually impaired individuals.
These findings have been divided into two distinct groups:
objective findings extracted from the quantitative data andsubjective findings extrapolated from discussions with theparticipants.
From the analysis of the questionnaires’ quantitative data,
the following findings can be highlighted:
1. Independently of their pathology, VI individuals request
face detection/recognition and text reading assistancefunctionalities. In addition, the current study clearlyhighlighted the desire of VI to have those functionalities regrouped on a common device.
2. Face recognition must be tailored according to thepathology and to each individual:• All considered pathologies experience difficulties

recognizing faces at a distance superior to one meter;• Face recognition at close distance must be tailoredfor each individual according to its preferences, there
is no common agreement amongst pathologies;• ONL expressed less interest in face recognition functionalities;• RP and Gl required face detection for peripheral
vision mainly (close and long range).

3. Face recognition should not be customized according
to familiarity of the person to recognize. Indeed participants reported the same difficulties whether trying
to recognize very familiar or less familiar persons.
4. Visual attention detection (detecting if an interlocutor islooking at them) in face-to-face and group discussions
is problematic for VI individuals; it could be supportedby smart glasses devices.
5. Recognition of facial expressions of emotion is not afunctionality requested by the majority of visually
impaired individuals.
6. Participants reported the importance of design and comfort of the assistive device.

Universal Access in the Information Society

7. The device should be able to provide physical means
to limit strong luminosity changes (ex. possibility touse physical shades): the RP, AMD and Gl populations
reported being particularly affected by strong luminosity
changes.
From the discussions and open questions from the questionnaire, the following aspects can be mentioned:
1. Smart glass devices are seen by most VI as a very promising technology for two main reasons, namely handsfree interaction and information contextualized according to head-gaze direction (head pointing direction).
2. Future developed systems should ensure the provided
feedback does not hinder the remaining senses of theuser when unsolicited; i.e. frequent and long audio notifications should be avoided whenever possible. Audio
channel is still considered by many individuals as the
optimal channel to convey large quantity of information.
3. Adaptive display of visual information is crucial toensure sufficient contrast (i.e. adaptive color palettes
based on context). Additional studies and experiments
will need to be performed in this domain.
4. The design of a device should avoid stigmatizing theuser or making him stand-out. This aspect seemed particularly important for the participants and echoes point(6) mentioned above.
5. It is important to provide the possibility to wear standard
glasses underneath the assistive device or use prescription lenses.

7 Conclusion
The current work provides, to our knowledge, the largest study focusing on needs and expectations of visually
impaired individuals for assistive smart glasses. The outcomes of the study are a set of questionnaires that provide
the possibility to assess the quality of life, functional difficulties and needs as well as technological expectations of
VIs and a set of findings highlighted from the analysis of
the questionnaire which should help guide future researches
in the field. The study, covering interviews with 50 participants having various VI pathologies, provides a detailed
view of the typical difficulties encountered by the different participants and their needs. The analysis of the results
provides insights on the needs and expectations according
to the distinct pathologies, highlighting the need of tailoredor highly customizable solutions for specific items. The setof findings, inferred from the analysis of the results and theinterviews resumes the most important elements that must
be addressed to successfully develop solutions for assistive
smart glasses that will ideally support VIs in their daily life.

In the future, concrete solutions for smart glasses will be
developed based on the main findings of the study; we notably plan to develop solutions specifically adapted to supportsocial functions such as face identification, visual attention
detection and recognition of facial expressions of emotion. A
second important future step is to extend the proposed questionnaire to cover feedback aspects. The types of feedback,their modulation and robustness to errors are key elements
to consider for a successful acceptation by visually impaired
individuals.
Acknowledgements The Authors gratefully acknowledge the grant
received from the Gelbert Fondation. The authors thank the SBV association, all the volunteers of the study and all the collaborators andstudents who worked on the different iterations of the project.
Declaration
Conflict of interest On behalf of all authors, the corresponding author
states that there is no conflict of interest.
Ethical approval Ethical approval was not required for this type ofstudy.
Informed consent All individual participants enrolled voluntarily inthe study from which data have been used for this work. They were
informed in detail, and informed consent was obtained from all ofthem.
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as longas you give appropriate credit to the original author(s) and the source,
provide a link to the Creative Commons licence, and indicate if changes
were made. The images or other third party material in this article areincluded in the article's Creative Commons licence, unless indicatedotherwise in a credit line to the material. If material is not included in
the article's Creative Commons licence and your intended use is not
permitted by statutory regulation or exceeds the permitted use, you willneed to obtain permission directly from the copyright holder. To view acopy of this licence, visit http://​creat​iveco​mmons.​org/​licen​ses/​by/4.​0/.

References
1. Ahmed, T., Kapadia, A., Potluri, V.: Up to a limit? privacy concerns of bystanders and their willingness to share additional
information with visually impaired users of assistive technologies. ACM Interact. Mob. Wear. Ubiquitous Technol. 2(89), 27(2018). https://​doi.​org/​10.​1145/​32648​99
2. Azenkot, S., Zhao, Y.: Designing smartglasses applications forpeople with low vision. ACM SIGACCESS Access. Comput. 119,
19–24 (2017). https://​doi.​org/​10.​1145/​31679​02.​31679​05
3. Bhowmick, A., Hazarika, S.M.: An insight into assistive technology for the visually impaired and blind people: state-of-the-art
and future trends. J. Multimodal User Interfaces 11(2), 149–172(2017). https://​doi.​org/​10.​1007/​s12193-​016-​0235-6
4. Bourne, R.R.A., Flaxman, S.R., Braithwaite, T., Cicinelli, M.V.,
Das, A., Jonas, J.B., Keeffe, J., Kempen, J.H., Leasher, J., Limburg, H., et al.: Magnitude, temporal trends, and projections of13

Universal Access in the Information Society

5.

6.

7.
8.

9.

10.

11.

12.

13.
14.

15.

16.
17.

18.

the global prevalence of blindness and distance and near vision
impairment: a systematic review and meta-analysis. Lancet Glob.
Health 5(9), e888–e897 (2017). https://​doi.​org/​10.​1016/​S2214-​109X(17)​30293-0
Buimer, H., Van Der Geest, T., Nemri, A., Schellens, R.,
Van Wezel, R., Zhao, Y.: Making facial expressions of emotions
accessible for visually impaired persons. In: ASSETS 2017—proceedings of the 19th International ACM SIGACCESS Conference
on Computers and Accessibility, vol. 46, pp. 331–332 (2017).
https://​doi.​org/​10.​1145/​31325​25.​31348​23
Caraiman, S., Morar, A., Owczarek, M., Burlacu, A., Rzeszotarski, D., Botezatu, N., Herghelegiu, P., Moldoveanu, F., Strumillo, P., Moldoveanu, A.: Computer vision for the visually
impaired: the sound of vision system. In: Proceedings—2017
IEEE International Conference on Computer Vision Workshops,
ICCVW 2017, pp. 1480–1489 (2017). https://​doi.​org/​10.​1109/​ICCVW.​2017.​175
Chaudhry, S., Chandra, R.: Design of a mobile face recognition
system for visually impaired persons. arXiv preprint (2015).
http://​arxiv.​org/​abs/​1502.​00756
Cimarolli, V.R., Boerner, K., Brennan-Ing, M., Reinhardt, J.P.,
Horowitz, A.: Challenges faced by older adults with vision loss:
a qualitative study with implications for rehabilitation. Clin.
Rehabil. 26(8), 748–757 (2012). https://​doi.​org/​10.​1177/​02692​
15511​429162
Congdon, N.G., Friedman, D.S., Lietman, T.: Important causesof visual impairment in the world today. J. Am. Med. Assoc.
290(15), 2057–2060 (2003). https://​doi.​org/​10.​1001/​jama.​290.​
15.​2057
Dakopoulos, D., Bourbakis, N.: Wearable obstacle avoidance
electronic travel aids for blind: a survey. IEEE Trans. Syst. Man.
Cybern. Part C (Appl. Rev.) 40(1), 25–35 (2010). https://​doi.​
org/​10.​1109/​TSMCC.​2009.​20212​55
Desrosiers, J., Wanet-Defalque, M.C., Tmisjian, K., Gresset, J.,
Dubois, M.F., Renaud, J., Vincent, C., Rousseau, J., Carignan,M., Overbury, O.: Participation in daily activities and social
roles of older adults with visual impairment. Disabil. Rehabil.
31(15), 1227–1234 (2009). https://​doi.​org/​10.​1080/​09638​28080​
25324​56
Elmannai, W., Elleithy, K.: Sensor-based assistive devices forvisually-impaired people: current status, challenges, and future
directions. Sensors (Switzerland) (2017). https://​doi.​org/​10.​3390/​s1703​0565
Faria, J., Lopes, S., Fernandes, H., Martins, P., Barroso, J.: Electronic white cane for blind people navigation assistance. In: World
Automation Congress (WAC), 2010 pp.1–7 (2010)
Fiannaca, A., Apostolopoulous, I., Folmer, E.: Headlock: A wearable navigation aid that helps blind cane users traverse large open
spaces. In: Proceedings of the 16th International ACM SIGACCESS Conference on Computers & Accessibility, ASSETS ’14,
pp. 19–26. Association for Computing Machinery, New York, NY,
USA (2014). https://​doi.​org/​10.​1145/​26613​34.​26614​53
Gori, M., Cappagli, G., Tonelli, A., Baud-Bovy, G., Finocchietti,
S.: Devices for visually impaired people: high technologicaldevices with low user acceptance and no adaptability for children. Neurosci. Biobehav. Rev. 69, 79–88 (2016). https://​doi.​org/​
10.​1016/j.​neubi​orev.​2016.​06.​043
Hu, M., Chen, Y., Zhai, G., Gao, Z., Fan, L.: An overview of assistive devices for blind and visually impaired people. Int. J. Robot.
Autom. (2019). https://​doi.​org/​10.​2316/J.​2019.​206-​0302
Huang, J., Kinateder, M., Dunn, M.J., Jarosz, W., Yang, X.D.,
Cooper, E.A.: An augmented reality sign-reading assistant forusers with reduced vision. PLoS ONE 14(1), 1–9 (2019). https://​doi.​org/​10.​1371/​journ​al.​pone.​02106​30
Hwang, A.D., Peli, E.: Augmented edge enhancement forvision impairment using google glas. In: Digest of Technical

13

19.

20.

21.

22.

23.

24.
25.

26.

27.

28.

29.

30.

31.

32.

33.

Papers—SID International Symposium, vol. 45, no. 1, pp. 305–
307 (2014). https://​doi.​org/​10.​1002/j.​2168-​0159.​2014.​tb000​82.x
Jafri, R., Ali, S.A., Arabnia, H.R., Fatima, S.: Computer visionbased object recognition for the visually impaired in an indoors
environment: a survey. Vis. Comput. 30(11), 1197–1222 (2014).
https://​doi.​org/​10.​1007/​s00371-​013-​0886-1
Krishna, S., Colbry, D., Black, J., Balasubramanian, V., Panchanathan, S.: A systematic requirements analysis and development ofan assistive device to enhance the social interaction of people whoare blind or visually impaired. In: Workshop on Computer Vision
Applications for the Visually Impaired (2008). http://​hal.​inria.​fr/​
inria-​00325​432
Liu, R., Salisbury, J.P., Vahabzadeh, A., Sahin, N.T.: Feasibilityof an autism-focused augmented reality smartglasses system forsocial communication and behavioral coaching. Front. Pediatr.
5(June), 1–8 (2017). https://​doi.​org/​10.​3389/​fped.​2017.​00145
Maidenbaum, S., Arbel, R., Buchs, G., Shapira, S., Amedi, A.:
Vision through other senses: Practical use of sensory substitution
devices as assistive technology for visual rehabilitation. In: 2014
22nd Mediterranean Conference on Control and Automation,
MED 2014 pp. 182–187 (2014). https://​doi.​org/​10.​1109/​MED.​
2014.​69613​68
Mangione, C.M., Lee, P.P., Gutierrez, P.R., Spritzer, K., Berry,S., Hays, R.D.: Development of the 25-item national eye institutevisual function questionnaire. Arch. Ophthalmol. (2001). https://​doi.​org/​10.​1001/​archo​pht.​119.7.​1050
Organization, W.H.: Global Initiative for the Elimination of
Avoidable Blindness: Action Plan 2006–2011. World HealthOrganization, Geneva (2007)
Phillips, M., Proulx, M.J.: Social interaction without vision: anassessment of assistive technology for the visually impaired. Technol. Innov. 20(1), 85–93 (2019). https://​doi.​org/​10.​21300/​20.1-​2.​
2018.​85
Qiu, S., Hu, J., Han, T., Osawa, H., Rauterberg, M.: Social glasses:
simulating interactive gaze for visually impaired people in faceto-face communication. Int. J. Hum. Comput. Interact. (2019).
https://​doi.​org/​10.​1080/​10447​318.​2019.​16965​13
Qiu, S., Hu, J., Rauterberg, M.: Nonverbal signals for face-to-facecommunication between the blind and the sighted. In: International Conference on Enabling Access for Persons with Visual
Impairment, February, pp. 157–165 (2015)
Ruffieux, S., Ruffieux, N., Caldara, R., Lalanne, D.: iknowu—
exploring the potential of multimodal are smart glasses for the
decoding and rehabilitation of face processing in clinical populations. In: Lecture Notes in Computer Science (including subseries
Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), vol. 10515 LNCS, pp. 423–432 (2017). https://​doi.​
org/​10.​1007/​978-3-​319-​67687-6_​28
Sandnes, F.E.: What Do Low-Vision Users Really Want from
Smart Glasses? Faces, Text and Perhaps No Glasses at All, pp.
187–194. Springer, New York (2016). https://​doi.​org/​10.​1007/​
978-3-​319-​41264-1_​25
dos Santos, A.D.P., Ferrari, A.L.M., Medola, F.O., Sandnes,
F.E.: Aesthetics and the perceived stigma of assistive technology
for visual impairment. Disab. Rehabil. Assist. Technol. (2020).
https://​doi.​org/​10.​1080/​17483​107.​2020.​17683​08
Sarfraz, M.S., Constantinescu, A., Zuzej, M., Stiefelhagen, R.: A
multimodal assistive system for helping visually impaired in social
interactions. Inf. Spekt. 40(6), 540–545 (2017). https://d​ oi.o​ rg/1​ 0.​1007/​s00287-​017-​1077-7
Shinohara, K., Wobbrock, J.O.: In the shadow of misperception:
assistive technology use and social interactions. In: Conferenceon Human Factors in Computing Systems—Proceedings, pp.
705–714 (2011). https://​doi.​org/​10.​1145/​19789​42.​19790​44
Suresh, A., Arora, C., Laha, D., Gaba, D., Bhambri, S.: Intelligent
smart glass for visually impaired using deep learning machineUniversal Access in the Information Society

34.

35.
36.

37.

38.

vision techniques and robot operating system (ros). In: Advancesin Intelligent Systems and Computing, vol. 751, pp. 99–112(2019). https://​doi.​org/​10.​1007/​978-3-​319-​78452-6_​10
Tanuwidjaja, E., Huynh, D., Koa, K., Nguyen, C., Shao, C.,
Torbett, P., Emmenegger, C., Weibel, N.: Chroma: A wearable
augmented-reality solution for color blindness. In: UbiComp
2014—-Proceedings of the 2014 ACM International Joint Conference on Pervasive and Ubiquitous Computing, pp. 799–810(2014). https://​doi.​org/​10.​1145/​26320​48.​26320​91
Tapu, R., Mocanu, B., Zaharia, T.: Wearable assistive devices forvisually impaired: A state of the art survey. Pattern Recogn. Lett.
(2018). https://​doi.​org/​10.​1016/j.​patrec.​2018.​10.​031
Terven, J.R., Salas, J., Raducanu, B.: New opportunities for computer vision-based assistive technology systems for the visually
impaired. Computer 47(4), 52–58 (2014). https://d​ oi.o​ rg/1​ 0.1​ 109/​
MC.​2013.​265
Washington, P., Wall, D., Voss, C., Kline, A., Haber, N., Daniels,
J., Fazel, A., De, T., Feinstein, C., Winograd, T.: Superpowerglass: a wearable aid for the at-home therapy of children with
autism. Proc. ACM Interact. Mobile, Wear. Ubiquitous Technol.
1(3), 1–22 (2017). https://​doi.​org/​10.​1145/​31309​77
Xu, Q., Chia, S.C., Mandal, B., Li, L., Lim, J.H., Mukawa, M.A.,
Tan, C.: SocioGlass: social interaction assistance with facerecognition on google glass. Sci. Phone Apps Mobile Devices
2(1), 7 (2016). https://​doi.​org/​10.​1186/​s41070-​016-​0011-8
39. Zhao, Y., Hu, M., Hashash, S., Azenkot, S.: Understanding low
vision people’s visual perception on commercial augmented
reality glasses. In: Conference on Human Factors in Computing
Systems—-Proceedings 2017-May, pp. 4170–4181 (2017). https://​doi.​org/​10.​1145/​30254​53.​30259​49
40. Zhao, Y., Kupferstein, E., Castro, B.V., Feiner, S., Azenkot, S.:
Designing ar visualizations to facilitate stair navigation for people
with low vision. In: Proceedings of the 32nd Annual ACM Symposium on User Interface Software and Technology, pp. 387–402.
ACM (2019). https://​doi.​org/​10.​1145/​33321​65.​33479​06
41. Zhao, Y., Wu, S., Reynolds, L., Azenkot, S.: A face recognition
application for people with visual impairments: Understanding
use beyond the lab. In: Conference on Human Factors in Computing Systems—Proceedings 2018-April, pp. 1–14 (2018). https://​doi.​org/​10.​1145/​31735​74.​31737​89
Publisher's Note Springer Nature remains neutral with regard tojurisdictional claims in published maps and institutional affiliations.

13