Abstract

Vision impairment (VI) affects more than 2.2 billion people worldwide, profoundly influencing their quality of life, social participation, and access to rehabilitation services. This narrative review examines key methodological strategies employed in social research on VI and rehabilitation, encompassing qualitative, quantitative, mixed-methods, and participatory approaches. It evaluates the strengths and limitations of these methodologies in capturing the diverse lived experiences of individuals with VI and in assessing rehabilitation outcomes. The review identifies several persistent challenges in the field, including the need to ensure accessibility in research instruments, achieve representative sampling across diverse populations, and address ethical considerations such as informed consent and confidentiality. It also discusses measurement difficulties, particularly in evaluating complex constructs like quality of life, social inclusion, and rehabilitation success, with special attention to cultural and contextual influences. Furthermore, the review emphasizes the importance of culturally sensitive and inclusive research designs, especially in settings constrained by limited resources and technological infrastructure. It highlights the impact of the digital divide and the barriers associated with assistive technology use, which may affect both data collection and participant engagement. The review advocates for participatory research models in which individuals with VI are actively engaged as co-researchers, ensuring that their perspectives directly inform research design and interpretation. Finally, the review calls for future research that prioritizes adaptive, inclusive, and culturally responsive methodologies to promote equitable and effective rehabilitation interventions. Such approaches are essential for advancing the quality of life and social well-being of individuals with VI globally.

Introduction

Vision impairment (VI) is a major global health concern, affecting more than 2.2 billion people worldwide and profoundly influencing functional capacity, psychosocial well-being, and social participation (1). Social research in this field seeks to understand the lived experiences of individuals with VI, identify barriers to inclusion, and evaluate the effectiveness of rehabilitation services and assistive technologies (2). The social dimensions of VI—encompassing stigma, social isolation, and accessibility—require methodological approaches that account for the specific needs and circumstances of this population (3).

Conducting research with individuals who have VI poses several methodological challenges, including ensuring accessibility of research instruments, achieving representative sampling across diverse populations, and addressing ethical considerations such as informed consent and confidentiality (4). Moreover, assessing complex constructs such as quality of life, social inclusion, and rehabilitation success demands methodological sensitivity to cultural, psychological, and environmental contexts. This review synthesizes the principal methodological strategies in social research on VI and rehabilitation, evaluates their respective strengths and limitations, and identifies key areas for further inquiry.

Transparency and Openness

In accordance with the Transparency and Openness Promotion guidelines, this narrative review incorporates several measures to ensure clarity and integrity throughout the review process:

• Literature Search and Selection Criteria: The literature search was conducted using clearly defined inclusion and exclusion criteria to achieve comprehensive and unbiased coverage of relevant studies. Details of the search strategy, including the databases consulted and specific search terms used, are detailed in the supplementary materials.

• Data Availability: As a narrative review synthesizing previously published studies, no new data were generated. However, all cited sources are publicly accessible, and complete references are provided to facilitate verification and replication of the review process.

• Preregistration: This review was not preregistered, as preregistration is typically not applicable to narrative reviews. Nevertheless, the methodology, including the review protocol, was designed to minimize potential bias by adhering best practices for systematic searching and study inclusion.

• Conflict of Interest and Funding: A declaration of potential conflicts of interest and funding sources is included in the manuscript to maintain transparency and ethical accountability in the research process.

• Open Access: The manuscript will be published in an open-access journal to promote broad dissemination and accessibility.

Methodological Strategies in Social Research on VI and Rehabilitation

Research on VI and rehabilitation employs a range of methodological strategies, each offering distinct advantages and limitations depending on the study objectives, population, and context. The primary approaches include qualitative, quantitative, mixed-methods, and participatory research designs. This section critically evaluates the advantages and challenges of each methodology and emphasizes the importance of context-specific application in VI research.

Qualitative Methods

• Qualitative approaches are fundamental for understanding the subjective experiences, psychosocial processes, and meaning-making associated with living with VI. These methods are particularly valuable in community-based or resource-limited settings where capturing localized realities and social dynamics is essential.

• In-depth Interviews: These allow for flexible, open-ended exploration of personal narratives, including psychological adjustment to VI. For example, Nakade et al. (5) used interviews to examine identity transformation and emotional adaptation following late-onset VI. Interview methods can be adapted using accessible formats, such as audio-recorded consent procedures or screen reader-compatible materials.

• Focus Groups: Group discussions facilitate shared experiences and peer dynamics, particularly regarding stigma, social support, and rehabilitation participation. Williams (6) demonstrated that focus groups with individuals with VI generated valuable insights into the role of peer support networks (7). However, this method may inadvertently exclude participants who experience social anxiety or require individualized communication accommodations.

• Case Studies and Ethnography: These methods provide in-depth contextual understanding, making them useful for examining long-term rehabilitation processes or challenges related to navigating public spaces and workplace environments (8). Although these methods provide rich, nuanced data, these are limited in generalizability due to small sample sizes and context-specific findings.

Critical Insight: Qualitative methods excel at capturing emotional, cultural, and lived-experience perspectives. These approaches are most effective in exploratory research phases or when informing program design, service design, and policy development.

Quantitative Methods

Quantitative designs provide measurable, comparable, and generalizable data on VI prevalence, intervention outcomes, and psychosocial indicators. These approaches are particularly well suited to clinical research, policy evaluation, and longitudinal analysis, where statistical rigor is essential.

• Surveys and Standardized Instruments: Instruments such as National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) and VI offer structured metrics of vision-related quality of life and functional impairment (9). While these tools are essential for assessing large-scale interventions, they may overlook subjective perceptions and culturally specific nuances.

• Longitudinal Studies: Tracking participants over extended periods enables the identification of rehabilitation trajectories and key adjustment factors (10). However, attrition, mobility limitations, and evolving support needs can compromise retention and the validity of data within VI populations.

• Experimental and Quasi-Experimental Designs: Randomized controlled trials (RCTs) remain the gold standard for determining intervention efficacy. Nevertheless, RCTs are often challenging in VI research due to limited sample sizes, ethical constraints, or difficulties in standardizing interventions. Quasi-experimental designs, which allow naturalistic group comparisons, therefore provide a more adaptable alternative (11).

Critical Insight: Quantitative methods generate robust evidence for policy and program validation, yet they depend on accessible and inclusive instruments and may insufficiently capture the emotional or social complexity of rehabilitation experiences.

Mixed-methods Approaches

Mixed-methods research integrates qualitative and quantitative techniques to encompass both the breadth and depth of rehabilitation experiences. This design is especially valuable when evaluating multifaceted programs that combine clinical care, psychological support, and assistive technology training.

For example, Stone (12) applied a mixed-methods framework to investigate the impact of assistive technology on social inclusion in low-income communities. Quantitative data measured device usage and satisfaction, while qualitative interviews revealed underlying barriers such as stigma and digital illiteracy.

Critical Insight: Mixed-methods designs effectively bridge gaps, but they require methodological alignment and advanced skills in data integration. They are particularly advantageous in program evaluation, where both stakeholder perspectives and quantifiable outcomes must both be addressed.

Participatory Research

Participatory research actively involves individuals with VI as co-researchers rather than passive participants. Grounded in principles of equity, empowerment, and inclusion, it hols particular relevance for disability research.

Veraart et al. (13) showed that participatory design enhanced the relevance and accessibility of survey instruments. Participants provided feedback on questionnaire layout, terminology, and dissemination strategies, ensuring cultural and contextual appropriateness.

Critical Insight: Participatory methods strengthens research legitimacy and foster community trust, particularly among marginalized groups. However, they require considerable time, training, and relationship-building, and may not always be feasible within institutional or funding constraints.

Comparative Evaluation of Methodologies

Each methodological approach serves distinct purposes depending on the research context:

• Clinical settings benefit most from quantitative and mixed-methods designs, where standardized data support clinical decision-making and service optimization.

• Community-based and culturally diverse contexts are best served by qualitative or participatory approaches that capture localized realties and enhance research relevance.

• Policy-driven studies frequently depend on quantitative evidence, yet integrating qualitative insights strengthens advocacy for inclusive services.

Although no single approach is universally optimal, effective research aligns the chosen methodology with the study context, adapt instruments for accessibility, and ensures meaningful participant engagement. Trade-offs between depth and generalizability, feasibility and rigor, or standardization and flexibility should be weighed carefully during study design.

To complement this analysis, Table 1 (added below) summarizes the principal characteristics, applications, and limitations of each methodological approach.

Key Methodological Issues and Challenges

• Accessibility and Inclusion: Ensuring accessibility in research instruments is essential. Standard printed questionnaires are inadequate for individuals with VI. Instruments must be available in alternative formats such as Braille, large print, or audio, and digital platforms should be compatible with screen readers and other assistive technologies (14). Failure to provide accessible materials can results in biased samples and the exclusion of certain participant groups (15).

• Sampling Difficulties: Recruitment challenges are substantial in VI research due to the geographic dispersion and diversity of the population. Convenience sampling is frequently employed, but this approach can introduce bias, particularly when specific subgroups, such as younger adults or urban residents, are overrepresented (16). Although purposive and snowball sampling techniques are useful for reaching specialized populations, they may also limit the generalizability of findings (12).

• Thical Considerations: Ensuring informed consent is critical in VI research. Consent forms should be available in accessible formats, and oral consent may be required for participants with limited literacy. Ethical considerations also extend to maintaining participant confidentiality, especially within smaller communities where individuals may be easily identifiable (17).

• Measurement Challenges: Measuring constructs such as quality of life and social inclusion presents significant methodological challenges. These constructs are inherently subjective and influenced by cultural and environmental factors (18). Standardized instruments, such as the NEI VFQ-25, may not fully capture the psychosocial and emotional dimensions of VI, highlighting the need for more sensitive and context-specific measures (10).

• Cultural and Contextual Sensitivity: The experience of VI varies across cultures, shaping perceptions of disability, rehabilitation, and social inclusion (19). Cross-cultural research must therefore consider language diversity, cultural variations in health perceptions, and local rehabilitation infrastructures. Studies conducted in low- and middle-income countries face additional challenges, including limited infrastructure, lower literacy levels, and greater technological constraints (20, 21).

Future Directions and Recommendations

To enhance inclusivity and methodological rigor in VI research, future studies should prioritize the following areas:

• Innovative Digital Tools: Continued development of accessible digital platforms is essential to promote broad participation, particularly among individuals with limited access to technology (14).

• Long-term Research: Longitudinal studies should be emphasized to evaluate the sustained effectiveness of rehabilitation interventions over time (10).

• Comprehensive Measurement: Future research should aim to develop more sensitive and culturally relevant measurement instruments that integrate qualitative and quantitative data, enabling a more nuanced understanding of the impact of VI on quality of life and rehabilitation success (12).

• Global Representation: Greater efforts are needed to ensure that research samples reflect the diversity of the VI population, including participants from rural areas, older age groups, and culturally varied backgrounds (11).

Conclusion

Research on VI and rehabilitation requires an integrated application of qualitative, quantitative, and mixed-methods approaches to address the diverse needs of this marginalized population. While qualitative methods yield deep insights into personal experiences, quantitative approaches provide generalizable evidence on prevalence and intervention efficacy. Key challenges, including accessibility, achieving representative sampling, ethical consent, and bias reduction, must be addressed through culturally sensitive research designs and precise measurement strategies. Future studies should emphasize methodological rigor in conjugation with the active participation of individuals with VI, ensuring the development of more effective, equitable, and inclusive rehabilitation services that enhance quality of life and social participation globally.