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Estimates of the prevalence of visual impairment caused by uncorrected refractive errors in 2004 have been determined at regional and global levels for people aged 5 years and over from recent published and unpublished surveys. The estimates were based on the prevalence of visual acuity of less than 6/18 in the better eye with the currently availab...
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Context 1
... blindness and low vision from uncor- rected refractive errors (this paper) and from all other causes (2002 estimate) are combined, 314 million people are visually impaired globally (Table 5). Uncorrected refractive errors are the second cause of blindness after cataract (Fig. 1) and the main cause of low vision: overall, they are the cause of almost half of all visual ...
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Aim:
The purpose of this study was to determine the prevalence of visual impairment and ocular morbidities among primary and secondary schoolchildren aged 5 years to <l6 years in Ifo, Ifo Local Government Area in Ogun State, Nigeria.
Materials and methods:
The study was a population-based descriptive cross-sectional study conducted among schoolc...
Purpose:
The prevalence of visual impairment due to uncorrected refractive error has not been previously studied in Canada. A population-based study was conducted in Brantford, Ontario.
Methods:
The target population included all people 40 years of age and older. Study participants were selected using a randomized sampling strategy based on post...
Estimates of the prevalence of visual impairment caused by uncorrected refractive errors in 2004 have been determined at regional and global levels for people aged 5 years and over from recent published and unpublished surveys. The estimates were based on the prevalence of visual acuity of less than 6/18 in the better eye with the currently availab...
Purpose
Undetected vision impairment (VI) could negatively affect the overall development in children. School vision screening program is a viable and cost-effective approach for the early identification and management of VI.
Aim
This study aims to estimate the prevalence of VI, its risk factors, and ocular morbidity among school children in Telan...
Background: Cataract is the leading cause of blindness globally and more people will be at risk for this common cause of vision loss in the coming years.
To estimate the disease burden of cataract and evaluate contributions of various risk factors to cataract-associated disability-adjusted life years (DALYs).
Methods: Prevalence of visual impairmen...
Citations
... The International Statistical Classification of Diseases, Injuries, and Causes of Death, 10 th revision (ICD-10), bases its definition of visual impairment on the best-corrected vision, i.e., visual acuity obtained with the best possible refractive correction. Visual impairment caused by uncorrected or inadequately corrected refractive errors is defined as visual acuity of less than 6/18 in the better eye that could be improved to equal to or better than 6/18 by refraction or pinhole, thus spanning the low vision and blindness categories as currently defined in the ICD-10 [9]. The current study uses the term visual impairment to include all degrees of impairment in addition to blindness. ...
Assistive technology (AT) has evolved rapidly and continues to develop among visually impaired students (VIS). The inclusion of VIS in mainstream education and employment is essential for building an inclusive society. However, it has been reported that VIS face numerous challenges in accessing and utilizing education and employment opportunities. This research paper aims to explore the effectiveness of assistive technology-based training in empowering VIS to become better future employees. The paper reviews various assistive technologies and their applications in facilitating learning and employment opportunities for visually impaired students. The study then uses a tri-level, mixed-method design to examine the impact of rehabilitative training that is based on assistive technology on the academic performance and employability of visually impaired students. The findings of the study reveal that assistive technology-based training has a significant positive impact on the academic performance and employability of VIS. The study recommends the integration of assistive technology-based training into the mainstream education system to provide equal learning and employment opportunities for visually impaired students.
... This can lead to significant economic and social problems in several aspects of a person's life. 1 Cycloplegic subjective refraction remains the gold standard for determining refractive error and the need for spectacle correction. [2][3][4][5][6] To assist with subjective refraction and, consequently, the prescription of spectacles, automated refraction (AR) devices have been increasingly refined and are becoming more portable Additionally, aberrometry devices now provide progressively more accurate AR. [5][6][7][8][9][10] More recently, self-refraction has been studied to correct refractive errors in adults, especially in areas with limited access to eye care providers. [10][11][12][13][14][15][16][17] These devices have been shown to provide clinically useful correction in adults. ...
Purpose
To compare the performance of a self-refraction device (EyeQue Vision Check 2, EyeQue, USA) with autorefraction (OPD-Scan III, NIDEK) and subjective cycloplegic refraction in measuring refractive errors.
Methods
This descriptive study included 80 eyes from 40 patients. Measurements were obtained using the portable EyeQue device, OPD-Scan III, and subjective cycloplegic refraction performed by an experienced examiner. Spherical equivalent (SE), cylindrical power, and axis values were analyzed using power vector decomposition (M, J0, J45) to improve accuracy in comparing methods. The main outcome was the agreement between self-refraction, autorefraction, and subjective refraction.
Results
The EyeQue device showed lower variability and greater homogeneity in spherical measurements but exhibited lower precision for cylindrical power and axis than subjective refraction. Power vector analysis revealed that EyeQue overestimated spherical equivalent (M) and produced higher J0 values, suggesting a tendency to alter cylindrical correction. Although comparable to OPD-Scan in spherical refraction, EyeQue demonstrated inconsistencies in astigmatism correction, particularly in J45 components.
Conclusion
The EyeQue device is a promising tool for large-scale screenings due to its affordability and portability. However, its limitations in astigmatism and axis measurements indicate that subjective refraction should complement rather than replace it. Therefore, further refinement and validation in diverse populations are recommended.
... Refractive error (RE) is one of the most common ophthalmologic disorders among children and adolescents worldwide and includes myopia, hyperopia and astigmatism. 1 It is reported that nearly 2.3 billion people worldwide live with RE, and this number is rising as the prevalence of myopia increases. 2 It is well known that a high rate of myopia occurs in East and Southeast Asian schoolchildren and young adults, with 67.3% of grade 7 children and 83.2% of university students affected in central China. ...
Background
Refractive surgery is gaining widespread popularity; however, there remains a limited understanding of the knowledge and attitudes of myopes regarding these procedures.
Objectives
To investigate the knowledge and attitudes of myopes or their guardians towards refractive surgery.
Design
Cross-sectional study.
Participants
581 myopes or their guardians in Suzhou City, Jiangsu Province, China, surveyed between August and October 2022.
Outcome measures
Knowledge and attitude scores before and after refractive surgery, ranging from 0 to 45 and 0 to 36, respectively.
Results
Postsurgery knowledge (32.35±11.48 vs 27.38±11.74, p<0.001) and attitude (27.77±3.505 vs 26.6±3.267, p<0.001) scores were significantly higher than presurgery scores. Participants showed insufficient knowledge but positive attitudes preoperatively, with significant improvements postoperatively. Factors influencing knowledge scores included education level (Ref. senior middle school or lower; junior college/college, OR=5.81, 95% CI 2.52 to 9.09, p=0.001; postgraduate or higher, OR=7.83, 95% CI 3.83 to 11.8, p<0.001) and survey timing (after refractive error surgery, OR=5.09, 95% CI 3.02 to 7.16, p<0.001), while attitude scores were influenced by knowledge scores (OR=0.05, 95% CI 0.03 to 0.07, p<0.001), gender (female, OR=1.24, 95% CI −2.8–−1.0, p<0.001), age (21–30 years old, OR=−1.9, 95% CI 2.52 to 9.09, p<0.001; >30 years old, OR=−2.5, 95% CI −3.5–−1.4, p<0.001) and survey timing (after refractive error surgery, OR=0.86, 95% CI 0.24 to 1.47, p=0.006).
Conclusions
Myopes or their guardians had positive attitudes towards refractive surgery both preoperatively and postoperatively. Insufficient knowledge prior to refractive surgery underscores the critical need for informed decision-making before undergoing the procedure.
... Uncorrected refractive errors are a significant cause of vision impairment and blindness, with the global average being 43% [1]. In 2010, refractive errors were the second leading cause of blindness after cataracts [2]. The challenge lies in correcting these errors globally, particularly in Africa, where vision impairment is higher in developing countries like Kenya [1]. ...
Background information: Refractive errors and presbyopia remain a burden to the entire population. An estimated 76% of the 191 million blind people have preventable or treatable causes. Uncorrected Refractive Error (URE), the number one cause (51%) of moderate and severe vision impairment, is easily preventable. Aim: The study aims to evaluate the accessibility, affordability, and acceptability of spectacles in Kakamega Municipality through a questionnaire. Methodology: A population-based descriptive cross-sectional study was undertaken in Kakamega municipality using a cluster sampling method and descriptive data analysis. Results: Out of 358 participants, 199 (55.6%) were male and 159 (44.4%) were female. The analysis shows affordability (18.3%) as the main reason for not using spectacles, followed by lack of quality care (3.4%), access to eye care (3.4%), awareness (2.5%), unpleasant past experiences (2.2%), importance not given to eye care issues (1.6%), lack of communication (0.9%), and disapproval from family members (0.9%). The study found that the affordable price range for spectacles varies between Kshs.5000. More participants (38.0%) reported above Kshs.5000, while 29% indicated less Kshs.2000. The study found that affordability (p = 0.000), availability (p = 0.004), and accessibility (p = 0.005) of refractive services significantly influenced the uptake of these services. Conclusion: The study reveals that refrac-tive services in Kakamega municipality are not easily accessible due to the lack of adequate services in government hospitals. Additionally, patients in the municipality struggle to afford spectacles due to the direct cost of spectacles and the lack of services in easily accessible public facilities.
... 3 Additionally, children with VI often struggle with social and recreational activities, with subsequent negative effects on their socioeconomic security, all impacting their quality of life. [3][4][5] The onset of VI before or during school-going age has a significant impact compared to that in adulthood, considering the greater number of years that they will likely carry this condition. 6 In the United States, it was reported that a person living with VI needs an estimated $4000 per annum for medical expenditure, an amount that increases with age, as it later includes the cost imposed by loss of productivity, anxiety, and frustrations linked to their disability. ...
... 9 The leading cause of VI in children is uncorrected or inappropriately corrected refractive error, attributing to about 12.8 million cases. 5 Ninety percent of children with VI reside in low-to-middle income countries (LMICs). 10,11 It is essential to understand the impact of VI on children's daily lives and their perceptions about their abilities and difficulties with daily activities to facilitate the development of appropriate management strategies. ...
Background/Purpose
There are approximately 18.94 million visually impaired children worldwide, with 90% of them living in low-middle income countries. Research shows that visual impairment (VI) has a significant impact on the quality of life (QoL) of those affected. Therefore, it is essential to investigate how VI affects the daily activities of these children to develop management strategies that can help minimize its impact on their QoL. Therefore, qualitative research design was utilized to explore the perceived impact of VI on the daily activities of children living with VI.
Methods
Using a qualitative approach, purposive sampling was used to identify information-rich participants to partake in focus group discussions (FGDs) and address the aim of the study adequately. Identified data sources were divided into two groups: one with ‘experts’ who worked with children regularly, and another with school-age children aged 6-17 years, from three rural schools in Sekhukhune district, South Africa. The FGDs were guided by semi-structured interview questions. All sessions were recorded, transcribed verbatim, cleaned, coded, and analysed under ten domains, identified from the literature.
Results
A total of 477 statements and comments related to children’s vision were generated through the nine FGDs. Participants were nine experts working with children, and 49 children living with or without VI. Of the total number of statements, 60% (n = 287) were generated from FGDs with children, 63% (n = 299) were negative statements, and the remaining 19% (n = 92), and 18% (n = 86) were neutral and positive statements respectively. The most generated statements fell under the domains ‘Hobbies, Leisure and Sport’ 21% (n = 101), ‘Education’ 21% (n = 100), and ‘Psychological and Emotional’ 12.8% (n = 61).
Conclusion
This study offered comprehensive insights into the impact of VI on the daily activities of rural school-aged children and young people.
... Uncorrected refractive error (URE) is a significant public health issue, particularly among children, and it significantly impacts academic performance and overall development [1][2][3][4][5][6][7][8][9][10]. This is evidenced by its inclusion in the priority areas of Vision 2020: The Right to Sight Program, a global initiative led by a consortium of non-governmental organizations and the World Health Organization [6,7]. ...
... Uncorrected refractive error (URE) is a significant public health issue, particularly among children, and it significantly impacts academic performance and overall development [1][2][3][4][5][6][7][8][9][10]. This is evidenced by its inclusion in the priority areas of Vision 2020: The Right to Sight Program, a global initiative led by a consortium of non-governmental organizations and the World Health Organization [6,7]. ...
This study compared the refraction measurements of the ClickCheck™ device (CCD), Topcon KR-8000, and subjective clinical refractometry (SCR) in Brazilian public school students with limited access to eye care. Eighty-seven eyes of healthy students aged 7 to 17 underwent refractometry using the CCD, Topcon KR-8000, and SCR methods under cycloplegia, with only the right-eye data analyzed. For comparison, the measurements were converted into spherical equivalents (SEs) and vector magnitudes. The mean SE difference between CCD and Topcon KR-8000 was −0.27 ± 0.58 (p < 0.0001), while the vector magnitudes at the 90 • and 135 • meridians were −0.23 ± 0.55 (p = 0.0001) and +0.04 ± 0.47 (p = 0.2246), respectively, demonstrating no clinical relevance. Similarly, the mean SE difference between CCD and SCR was −0.18 ± 0.58 (p = 0.065), with vector magnitudes of −0.20 ± 0.50 (p = 0.0003) at 90 • and +0.03 ± 0.46 (p = 0.3730) at 135 • , also lacking clinical relevance. Despite statistically significant differences between the methods, the findings confirm strong agreement, validating CCD as an effective refractive assessment tool for children in low-resource settings. These methods can enhance access to refraction services in underserved populations.
... Glaucoma is a chronic, sight-threatening condition that results from the progressive loss of retinal ganglion cells (RGCs) and often leads to irreversible visual impairment. It is the third most common cause of visual deficits worldwide, after cataracts and uncorrected refractive errors [1]. Elevated intraocular pressure (IOP) remains the sole modifiable risk factor for glaucoma. ...
Background
In patients with advanced glaucoma, lesions frequently extend beyond the eye and affect other organs. However, early distal consequences of elevated intraocular pressure (IOP) remain unclear. This study aimed to observe glucose uptake in the optic cortex during the early stages of elevated IOP and to investigate the mechanism by which Apelin13 exerts neuroprotective effects.
Methods
This study used a single anterior chamber injection of polystyrene microbeads and triblock copolymer hydrogel in 6- to 8-week-old male C57BL/6J mice and observed glucose uptake in the optic cortex during the initial phase of IOP elevation using micro-positron emission tomography/magnetic resonance imaging (PET/MRI). Pathological changes in the optic nerve and optic cortex were assessed by immunofluorescence, reactive oxygen species (ROS) kit, and and nicotinamide adenine dinucleotide phosphate (NADPH) kit. Expression of glucose transporter proteins (GLUTs) and key enzymes of the pentose phosphate pathway (PPP) was evaluated using immunofluorescence and western blot. The activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B signaling pathway was analyzed via western blot.
Results
On day 1 of elevated IOP, the modeled eye exhibited reduced glucose uptake in the corresponding visual cortex compared with the contralateral visual cortex. Over time, the condition gradually improved, with no discernible difference between the two sides by day 21. Concurrently, along with abnormal activation of microglia and progressive reduction of retinal ganglion cells, we noted abnormal expression of glucose transporter proteins in visual cortical neurons. Additionally, elevated levels of ROS and NADPH were observed in both the retinal and brain tissues following IOP elevation. In contrast, administration of the neuroprotectant Apelin-13 mitigated the pathology induced by IOP elevation. Conversely, treatment with a PI3K inhibitor significantly diminished the protective effects of Apelin-13.
Conclusions
These findings imply that altered glucose metabolism in the visual center may be an early sign of optic nerve damage in patients with glaucoma. Apelin-13 may rely on the PI3K/Akt signaling pathway to regulate the redistribution of energy metabolism in the retina and visual centers, thereby mitigating oxidative stress and safeguarding neuronal cells.
... The global economic burden of distance vision impairment due to uncorrected refractive errors is estimated to be $220 billion, while the cost for training and service delivery facilities is only $28 billion. Accessibility and affordability are key factors affecting the uptake of refractive services [3,4,5] . Universal eye health is needed to provide 100% universal access to healthcare [7] . ...
Background information: Refractive errors and presbyopia remain a burden to the entire population. An estimated 76% of the 191 million blind people have preventable or treatable causes. Uncorrected Refractive Error (URE), the number one cause (51%) of moderate and severe vision impairment is easily preventable. Aim: The aimed to assess myths and community beliefs as barriers to the uptake of refractive services in Kakamega municipality residents aged 18 to 60 years. Methodology: A population-based descriptive cross-sectional study was undertaken in Kakamega municipality using a cluster sampling method and descriptive data analysis. Results: Out of 358 participants, 199 (55.6%) were male and 159 (44.4%) were female. The majority of participants reported that spectacles spoil the eyes 150 (50.8%). Other associated myths were that spectacles worsen the eye problem (5.4%), spectacles are a sign of cleverness (3.4%), spectacles are for people with esteemed status (2.4%, spectacles improve the eyes (2.0%), spectacles are a sign of arrogance(1.7%), spectacles make the eyes appear sunken (1.3%), spectacles are due to an inherited condition (1.0%), people wearing spectacles are seen as being cursed (0.7%), spectacles are for mean people (0.3%) and people wearing spectacles are valued as being disabled (0.3%). Age was significantly associated with the use of spectacles (p=0.024). Gender distribution (p=0.758), education level (p= 0.962) and occupation (p=0.207) were not significantly associated with the use of spectacles. Individual perception on the use of spectacles (p= 0.050), community perception on female using spectacles (p=0.000), gender hindrance to the use of spectacles (p=0.013), spectacles affecting sports (p=0.001), were significantly associated with the use of spectacles. Conclusion: The study came to a conclusion that negative perception towards wearing spectacles as a barrier to the uptake of refractive services. Community education regarding refractive services will also greatly boost the uptake of refractive services.
... Refractive errors are the leading cause of preventable visual impairment (VI) worldwide 1,2 . For adults and children, myopia is the predominant refractive error 3 . ...
... Implications of VI are severe; over $205 billion is estimated in reduced productivity yearly due to refractive errors for mild, moderate, and severe VI 7 . This is compounded by lagging academic and personal development, reduced quality of life, increased mortality, and depression 1,2,[8][9][10][11][12][13] . The biggest drivers for uncorrected refractive errors (URE) are population growth, environmental factors, and lack of access to health care 14,15 . ...
Refractive errors are the leading cause of preventable visual impairment, to which web-based remote refraction could contribute. We report real-world 2021–2022 data of the underlying algorithm and validated these to conventional prescriptions among healthy individuals (high visual acuity and satisfactied current refraction). Participants were 18–45 years with a spherical (S) error between −3.50 + 2.00S to −2.00 Diopter Cylinder (DC), reported as Spherical Equivalent (SEQ) in mean differences and 95% Limits of agreement. Consecutive measurements ( n = 14,680) were assessed of which n = 6386 selected for validation. The mean difference was 0.01D(SD 0.69) and −0.73D(SD 0.92) for myopes and hyperopes respectively. This algorithm shows variation, nonetheless, 67% and 82% of myopes were within ±0.5 and ±0.75D. The test underestimates hyperopes (34% and 50% within ±0.5D and ±0.75D) and had inconsistencies distinguishing hyperopia. This proof-of-concept shows home testing has the potency to increase accessibility to care by delivering a valuable alternative for uncomplicated refractive assessments.
... Most of the participants were unskilled workers (33.9%), followed by skilled workers (25.8%) and professionals (21.0%). The high prevalence of low vision among unskilled workers may be due to increased exposure to environmental and occupational risks without adequate protection or preventive measures 21 . Moreover, individuals in lower socio-economic brackets tend to have reduced access to healthcare services, contributing to untreated or poorly managed eye conditions 22 . ...
Introduction: Low vision is a significant global public health issue, affecting millions and leading to reduced quality of life. In developing countries like Bangladesh, low vision is often due to uncorrected refractive errors, cataracts, and other preventable conditions. There are disparities in the prevalence and causes of low vision between urban and rural populations, driven by differences in healthcare access, socio-economic status, and awareness. Objective: To assess the prevalence, causes, and socio-economic impact of low vision in urban and rural populations in Bangladesh. Method and Materials: This cross-sectional comparative study was conducted at the Ophthalmology Department, Shaheed Tajuddin Ahmed Medical College, Gazipur, over two years (January 2021–December 2022). A total of 124 participants were included using stratified random sampling. Comprehensive eye exams and demographic data were collected. The study used descriptive statistics and chi-square tests for analysis, with a p-value of <0.05 considered significant. Result: The study included 124 participants, with the majority aged 30–49 (33.9%) and 56.5% being male. Half of the participants (50%) had moderate low vision, while 37.1% had severe low vision. Cataracts were the leading cause of low vision (38.7%), especially in rural areas (46.7%). Urban participants had more frequent eye check-ups (81.3%) and cataract surgeries (21.9%) compared to rural participants (46.7% and 13.3%, respectively). Conclusion: The study reveals disparities in low vision prevalence, causes, and access to care across populations. Medicine Today 2025, Vol.37 (1): 78-82
