Prevalence of visual impairment and estimation of refractive errors among school children in Kakamega,Kenya

AIM:To investigate the prevalence of visual impairment(VI)and provide an estimation of uncorrected refractive errors in school-aged children,conducted by optometry students as a community service.METHODS:The study was cross-sectional.Totally 3343 participants were included in the study.The initial examination involved assessing the uncorrected distance visual acuity(UDVA)and visual acuity(VA)while using a+2.00 D lens.The inclusion criteria for a subsequent comprehensive cycloplegic eye examination,performed by an optometrist,were as follows:a UDVA<0.6 decimal(0.20 logMAR)and/or a VA with+2.00 D≥0.8 decimal(0.96 logMAR).RESULTS:The sample had a mean age of 10.92±2.13y(range 4 to 17y),and 51.3%of the children were female(n=1715).The majority of the children(89.7%)fell within the age range of 8 to 14y.Among the ethnic groups,the highest representation was from the Luhya group(60.6%)followed by Luo(20.4%).Mean logMAR UDVA choosing the best eye for each student was 0.29±0.17(range 1.70 to 0.22).Out of the total,246 participants(7.4%)had a full eye examination.The estimated prevalence of myopia(defined as spherical equivalent≤-0.5 D)was found to be 1.45%of the total sample.While around 0.18%of the total sample had hyperopia value exceeding+1.75 D.Refractive astigmatism(cil<-0.75 D)was found in 0.21%(7/3343)of the children.The VI prevalence was 1.26%of the total sample.Among our cases of VI,76.2%could be attributed to uncorrected refractive error.Amblyopia was detected in 0.66%(22/3343)of the screened children.There was no statistically significant correlation observed between age or gender and refractive values.CONCLUSION:The primary cause of VI is determined to be uncorrected refractive errors,with myopia being the most prevalent refractive error observed.These findings underscore the significance of early identification and correction of refractive errors in school-aged children as a means to alleviate the impact of VI.

Uncorrected refractive errors are important causes of avoidable visual impairment in Hungary: re-evaluation of two existing national data sets

·AIM: To review existing data for the prevalence of corrected, uncorrected, and inadequately corrected refractive errors and spectacle wear in Hungary.·METHODS: Data from two nationwide cross-sectional studies were analysed. The Rapid Assessment of Avoidable Blindness study collected population-based representative national data on the prevalence of visual impairment due to uncorrected refractive errors and spectacle coverage in 3523 people aged ≥50y(Group I). The Comprehensive Health Test Program of Hungary provided data on the use of spectacles in 80 290 people aged ≥18y(Group Ⅱ).·RESULTS: In Group I, almost half of the survey population showed refractive errors for distant vision, about 10% of which were uncorrected(3.2% of all male participants and 5.0% of females). The distance spectacle coverage was 90.7%(91.9% in males;90.2% in females). The proportion of inadequate distance spectacles was found to be 33.1%. Uncorrected presbyopia was found in 15.7% of participants. In all age groups(Group Ⅱ), 65.4% of females and 56.0% of males used distance spectacles,and approximately 28.9% of these spectacles were found to be inappropriate for dioptric power(with 0.5 dioptres or more). The prevalence of inaccurate distance spectacles was significantly higher in older age groups(71y and above) in both sexes.·CONCLUSION: According to this population-based data, uncorrected refractive errors are not rare in Hungary. Despite recent national initiatives, fur ther steps are required to reduce uncorrected refractive errors and associated negative effects on vision, such as avoidable visual impairment.

Red Deer Optimization with Artificial Intelligence Enabled Image Captioning System for Visually Impaired People

The problem of producing a natural language description of an image for describing the visual content has gained more attention in natural language processing(NLP)and computer vision(CV).It can be driven by applications like image retrieval or indexing,virtual assistants,image understanding,and support of visually impaired people(VIP).Though the VIP uses other senses,touch and hearing,for recognizing objects and events,the quality of life of those persons is lower than the standard level.Automatic Image captioning generates captions that will be read loudly to the VIP,thereby realizing matters happening around them.This article introduces a Red Deer Optimization with Artificial Intelligence Enabled Image Captioning System(RDOAI-ICS)for Visually Impaired People.The presented RDOAI-ICS technique aids in generating image captions for VIPs.The presented RDOAIICS technique utilizes a neural architectural search network(NASNet)model to produce image representations.Besides,the RDOAI-ICS technique uses the radial basis function neural network(RBFNN)method to generate a textual description.To enhance the performance of the RDOAI-ICS method,the parameter optimization process takes place using the RDO algorithm for NasNet and the butterfly optimization algorithm(BOA)for the RBFNN model,showing the novelty of the work.The experimental evaluation of the RDOAI-ICS method can be tested using a benchmark dataset.The outcomes show the enhancements of the RDOAI-ICS method over other recent Image captioning approaches.

IoT-Driven Optimal Lightweight RetinaNet-Based Object Detection for Visually Impaired People

Visual impairment is one of the major problems among people of all age groups across the globe.Visually Impaired Persons(VIPs)require help from others to carry out their day-to-day tasks.Since they experience several problems in their daily lives,technical intervention can help them resolve the challenges.In this background,an automatic object detection tool is the need of the hour to empower VIPs with safe navigation.The recent advances in the Internet of Things(IoT)and Deep Learning(DL)techniques make it possible.The current study proposes IoT-assisted Transient Search Optimization with a Lightweight RetinaNetbased object detection(TSOLWR-ODVIP)model to help VIPs.The primary aim of the presented TSOLWR-ODVIP technique is to identify different objects surrounding VIPs and to convey the information via audio message to them.For data acquisition,IoT devices are used in this study.Then,the Lightweight RetinaNet(LWR)model is applied to detect objects accurately.Next,the TSO algorithm is employed for fine-tuning the hyperparameters involved in the LWR model.Finally,the Long Short-Term Memory(LSTM)model is exploited for classifying objects.The performance of the proposed TSOLWR-ODVIP technique was evaluated using a set of objects,and the results were examined under distinct aspects.The comparison study outcomes confirmed that the TSOLWR-ODVIP model could effectually detect and classify the objects,enhancing the quality of life of VIPs.

Deep learning-based automated grading of visual impairment in cataract patients using fundus images

Cataract is the leading cause of visual impairment globally.The scarcity and uneven distribution of ophthalmologists seriously hinder early visual impairment grading for cataract patients in the clin-ic.In this study,a deep learning-based automated grading system of visual impairment in cataract patients is proposed using a multi-scale efficient channel attention convolutional neural network(MECA_CNN).First,the efficient channel attention mechanism is applied in the MECA_CNN to extract multi-scale features of fundus images,which can effectively focus on lesion-related regions.Then,the asymmetric convolutional modules are embedded in the residual unit to reduce the infor-mation loss of fine-grained features in fundus images.In addition,the asymmetric loss function is applied to address the problem of a higher false-negative rate and weak generalization ability caused by the imbalanced dataset.A total of 7299 fundus images derived from two clinical centers are em-ployed to develop and evaluate the MECA_CNN for identifying mild visual impairment caused by cataract(MVICC),moderate to severe visual impairment caused by cataract(MSVICC),and nor-mal sample.The experimental results demonstrate that the MECA_CNN provides clinically meaning-ful performance for visual impairment grading in the internal test dataset:MVICC(accuracy,sensi-tivity,and specificity;91.3%,89.9%,and 92%),MSVICC(93.2%,78.5%,and 96.7%),and normal sample(98.1%,98.0%,and 98.1%).The comparable performance in the external test dataset is achieved,further verifying the effectiveness and generalizability of the MECA_CNN model.This study provides a deep learning-based practical system for the automated grading of visu-al impairment in cataract patients,facilitating the formulation of treatment strategies in a timely man-ner and improving patients’vision prognosis.

Prevalence and Factors Associated with Refractive Errors among University Students at Mbarara University of Science and Technology, Uganda

Introduction: WHO estimated that uncorrected refractive errors are the leading cause of visual impairment and second leading cause of blindness globally. University students are prone to developing refractive errors due to their curriculum that requires a lot of near work affecting their performance and quality of life unknowingly. Genetic and environmental factors are thought to play a role in the development of refractive errors. This study addresses the paucity of knowledge about refractive errors among university students in East Africa, providing a foundation for further research. Objectives: To determine the prevalence and factors associated with refractive errors among students in the Faculty of Medicine at Mbarara University of Science and Technology. Methodology: This was a cross-sectional descriptive and analytical study in which 368 undergraduate students selected using random sampling were assessed for refractive errors from March 2021-July 2021. Eligible participants were recruited and their VA assessment done after answering a questionnaire. Students whose VA improved on pin hole had subjective retinoscopy and results were compiled and imported to STATA 14 for analysis. Results: The prevalence of refractive errors was 26.36% with (95% CI) among university students especially myopia. Myopia is most predominant at 60%, followed by 37% Astigmatism and hyperopia of 3% among medical students. Astigmatism consisted of largely myopic astigmatism 72% (26) and 28% (10) compound/mixed astigmatism only. Student positive family history of refractive error was found to have a statistically significant relationship with refractive errors with AOR 1.68 (1.04 - 2.72) (95% CI) and P (0.032). Conclusion: The prevalence of refractive errors among university students, especially myopia, was found to be high and family history was associated with students having refractive errors.

Population-based survey of prevalence,causes,and risk factors for blindness and visual impairment in an aging Chinese metropolitan population

AIM： To assess the prevalence, causes, and risk factors for blindness and visual impairment among elderly （〉60 years of age） Chinese people in a metropolitan area of Shanghai, China. METHODS： Random cluster sampling was conducted to identify participants among residents ≥60 years of age living in the Xietu Block, Xuhui District, Shanghai, China. Presenting visual acuity （PVA） and best-corrected visual acuity （BCVA） were checked by the Early Treatment Diabetic Retinopathy Study （ETDRS） visual chart. All eligible participants underwent a comprehensive eye examination. Blindness and visual impairment were defined according to World Health Organization （WHO） criteria. RESULTS： A total of 4190 persons （1688 men and 2502 women） participated in the study, and the response rate was 91.1%. Based on PVA, the prevalence of blindness was 1.1% and that of visual impairment was 7.6%. Based on BCVA, the prevalence of blindness and visual impairment decreased to 0.9% and 3.9%, respectively. Older （〉80 years of age） women, with low educational levels and smoking habits, exhibited a significantly greater chance for blindness and visual impairment than did those with high educational levels and no smoking habits （P〈0.05）. Based on PVA and BCVA, the main causes of blindness were cataract, myopic maculopathy, and age-related macular degeneration （AMD）. CONCLUSION： Our findings help to identify the population in need of intervention, to highlight the need for additional eye healthcare services in urban China.

Frequency of presenting visual acuity and visual impairment in Chinese college students

AIM:To obtain the baseline data on presenting visual acuity(PVA)and evaluate the prevalence and associated factors for visual impairment based on PVA in 9070 Chinese college students.METHODS:The freshmen at a university in southern China,including 6527 undergraduate students and 2543 graduate students,were investigated for some sociodemographic characteristics and underwent routine medical examination,including measuring PVA,height,and weight.Visual impairment was defined according to the new World Health Organization criteria for blindness and visual impairment.RESULTS:In 9070 college students,the mean PVA in the better eye was 0.094±0.163 log MAR.The prevalence of visual impairment based on PVA was 2.7%.Only 38.3%college students had normal visual acuity[PVA equal to 0 log MAR(20/20)in both eyes].There were 69.8%of students wearing spectacles.Logistic regression showed that home region(non-Guangdong provinces,P<0.0001,OR=1.70)was risk factor for visual impairment while BMI(P=0.001,OR=0.92)was protective factor from visual impairment.Ethnicity(Han Chinese,P<0.0001,OR=3.17)was risk factor for wearing spectacles while age(P=0.01,OR=0.90)was protective factor from wearing spectacles.CONCLUSION:This study provides the baseline data on PVA and the prevalence of visual impairment in Chinese college students.Our analyses reveal that BMI and home region are associated factors for visual impairment based on PVA,while age and ethnicity are associated factors for wearing spectacles.

Visual impairment and depression: Age-specific prevalence, associations with vision loss, and relation to life satisfaction

BACKGROUND To our knowledge,no study has obtained specific estimates of depression for young and middle-aged adults with visual impairment(VI).As estimates of depression varies across age groups in the general population,it is of interest to examine whether the same applies to adults with low vision or blindness.AIM To estimate depression prevalence and its association with VI-related characteristics and life satisfaction in adults with VI.METHODS A telephone-based cross-sectional survey was conducted between January and May 2017 in an age-stratified sample of adults who were members of the Norwegian Association of the Blind and Partially Sighted.Participants were asked questions about their sociodemographic characteristics,VI characteristics,and life satisfaction.Depression was measured with the Patient Health Questionnaire.The diagnostic scoring algorithm was used to calculate the point prevalence of depression(i.e.,major depression and other depressive disorders)across categories of gender and age(years:18-35,36-50,51-65,≥66).The associations were estimated using regression models.RESULTS Overall,736 adults participated in the study(response rate:61%).The prevalence estimates of depression varied across different age groups,ranging from 11.1%-22.8%in women and 9.4%-16.5%in men,with the highest rates for the two youngest age groups.Results from the multivariable models including sociodemographic and VI-related variables showed that losing vision late in life[Prevalence ratio(PR),1.76,95%CI:1.11,2.79]and having other impairments(PR:1.88,95%CI:1.32,2.67)were associated with higher rates of depression,whereas older age was associated with lower rates(PR:0.83,95%CI:0.74,0.93).Additionally,participants who were depressed had lower life satisfaction than those who were not depressed(adjustedβ:-2.36,95%CI:-2.75,-1.98).CONCLUSION Our findings suggest that depression in adults with VI,and especially among young and middle-aged adults,warrants greater attention by user organisations,clinicians,and healthcare authorities.

Prevalence of visual impairment and related factors in Nangarhar Province of Afghanistan:a cross sectional study

AIM: To determine the prevalence, main causes, and related factors of visual impairment(VI) among people aged 50 y and over in Jalalabad City and four surrounding districts of Nangarhar Province of Afghanistan. METHODS: The data for the population based crosssectional study was collected in 2015. The calculated sample size was 1353, allocated to urban-rural strata using probability proportion to size method. At the end of the study, 1281 people participated in to the study. VI was defined as presenting visual acuity(VA) of less than 6/18 and blindness as VA less than 3/60 in the better eye by using Snellen chart only. Data was analyzed using IBM SPSS 21.0 software.RESULTS: The prevalence of VI was 22.6%(95%CI, 20%-25%) of which 13.9%(95%CI, 12%-16%) was low vision and 8.7%(95%CI, 7%-10%) was blindness. The most common causes of the VI were cataract(52.8%), followed by uncorrected refractive error(URE)(26.9%) and glaucoma(8.6%). Number one cause of the low vision was URE(42%), followed by cataract, glaucoma, age-related macular degeneration(AMD) and diabetic retinopathy(DR), while for blindness they are cataract(72%), other posterior segment disorders, glaucoma, URE and AMD. Illiteracy, bad economic status, hypertension and overweight were factors independently associated with both VI and low vision, whereas, age, illiteracy, bad economic status, hypertension and using of sunglasses were independently associated with blindness.CONCLUSION: Cataract, URE, glaucoma, AMD and DR are the leading causes of VI and blindness in the study area. They are mostly avoidable. In order to decrease theburden of VI and blindness in the study area as well as the whole country, it is strongly recommended to apply the prevention policies of VI and blindness.

Unilateral visual impairment in rural south India-Andhra Pradesh Eye Disease Study(APEDS)

AIM： To report the prevalence and causes of unilateral visual impairment（UVI） in rural population of all ages in rural Andhra Pradesh, India.·METHODS： A population-based cross sectional study using a multi-stage cluster sampling methodology was carried out in West Godavari, Adilabad and Mahbubnagar districts in south India. A comprehensive eye examination that included presenting and best corrected visual acuity and dilated fundus examination was conducted by trained professionals. UVI is defined as presenting visual acuity 6/18 in one eye but ≥6/18 in other eye. Multiple logistic regression analysis was used to test association of UVI with socio-demographic risk factors.· RESULTS： Data were analyzed for 6634/7771 participants after excluding those with bilateral visual impairment. The mean age of the participants was 27.4y（Standard deviation： 17.9y）, 51.9% were women and49.1% were educated. The prevalence of UVI was 7.8%（95% CI： 7.2%- 8.5%）. Uncorrected refractive error（60.8%）, cataract（17.4%） and retinal causes（6.6%） were the leading causes of UVI. On multiple logistic regression analyses, older age, not having education, living in welloff district had significantly higher odds of being associated with UVI. UVI was not associated with gender.·CONCLUSION： UVI is common in rural south India.Most of it is due to cataract and refractive errors, both of which can be addressed at primary and secondary levelsof eye care. Burden of UVI should also be considered in planning eye care services.

Prevalence of visual impairment and refractive errors in an urban area of Mexico

AIM: To determine the distribution of refractive errors in a school-age population in Quintana Roo(Mexico) in the framework of an international cooperation campaign for the prevention of blindness. METHODS: A sample of 2647 school-age children(ranging from 5 to 14 years old) with a mean age of 9.1±1.9 years old were tested by trained volunteers for distance visual acuity(VA) and refractive errors. The first screening examination included uncorrected distance visual acuity(UDVA) and VA with a +2.00 D lens. Inclusion criteria for a second complete cycloplegic eye examination performed by an optometrist were UDVA <20/25(0.10 logMAR or 0.8 decimal) and/or VA with +2.00 D ≥20/25.RESULTS: A total of 633(23.9%) children underwent the second complete eye examination. Mean logMAR UDVA was 0.035±0.094(range 1.00 to 0.00 logMAR) for the right eyes and 0.036±0.160(range 1.00 to 0.00 logMAR) for the left eyes. Bilateral amblyopia was found in 17 children(2.7% of refracted eyes;0.64% of the total). The main reason for visual impairment(VI) in the sample analyzed was found to be refractive errors. In 12 children(1.9% of refracted eyes;0.45% of the total) the VI was bilateral and 9(1.4% of refracted eyes;0.34% of the total) achieved a corrected distance visual acuity of 20/25 or better in both eyes. Mean magnitude of sphere and refractive cylinder was +0.20±0.96 D and-0.43±0.85 D in right eyes, and +0.24±1.08 and-0.43±0.83 D in left eyes. The proportion of myopic eyes [standard equivalent(SE) ≤-0.50 D] was 4.6% of the whole sample(5290 eyes). The mean magnitude of myopia was-0.84±3.44 D for the right eyes and-0.82±5.21 D for the left eyes. The proportion of hyperopic patients(SE≥+2.00 D) was 2.4%(15/633), which corresponded to 0.60% of the whole sample(32/5290 eyes). No statistically significant correlation of age to manifest sphere or cylinder was found.CONCLUSION: VI due to uncorrected refractive errors can be easily corrected with glasses but it is still a burden to be treated. Myopia is prevalent in this sample. More efforts towards correcting uncorrected refractive errors are needed.

Socio-economic disparity in visual impairment from cataract

AIM:To investigate the association of visual impairment from cataract with human development index(HDI)by years lived with disability(YLDs).METHODS:Published data on national age-standardized YLD rates caused by cataract and national HDIs in 2019 were obtained.Age-standardized YLD rates from 1990 to 2019 were analyzed to explore cataract burden among patients with different income levels.Age-standardized YLD rates in different HDI groups were compared by different degrees of visual impairment.Association between national age-standardized YLD rates and HDI in 2019 was analyzed.RESULTS:The age-standardized YLD rates of populations with visual impairment or blindness due to cataract declined from 1990 to 2019,especially among those with lower middle income.Multiple comparison tests revealed that countries with low HDI had significantly higher agestandardized YLD rates of blindness due to cataract than those with high and very high HDI(P<0.001).The agestandardized YLD rates of populations with blindness(β=-0.588,P<0.001),severe vision loss(β=-0.378,P<0.001),and moderate vision loss(β=-0.389,P<0.001)inversely correlated with HDI.CONCLUSION:Age-standardized YLD rates caused by cataract have declined since 1990.The burden of visual impairment due to cataract inversely correlate with national socioeconomic development and is more concentrated in countries with low HDI than those with high HDI,especially among the blind.These findings highlight the need to provide additional cataract services and cataract surgery coverage to developing countries to decrease the burden of avoidable blindness caused by cataract.

Utilization of eye care services among those with unilateral visual impairment in rural South India：Andhra Pradesh Eye Disease Study(APEDS)

AIM：To report on the utilization of eye care services and its associated factors among those with unilateral visual impairment（VI）in a rural South Indian population.METHODS：A population based cross-sectional study was conducted in three districts（Adilabad,Mahbubnagar and West Godavari）in the state of Andhra Pradesh,India.A detailed interview and a comprehensive eye examination were conducted. Those with unilateral VI were asked questions about noticing any change in vision and on utilization of eye care services. The most important reason reported by the participant for not utilizing the services was used for the analysis. Multiple logistic regression models were used to examine the association between noticing a change in vision and socio-demographic variables such as age,gender,education and area of residence,severity and causes of VI.RESULTS：Among the 4456 participants aged ≥16y who were administered the questionnaire,53.2% were women,and 54.7% had no education. Of the 489（11%; 95% CI：10.1-11.9）people with unilateral VI,399（81.6%）participants reported noticing a change in their vision over the last five years but only 136（34.1%）participants had soughteye care consultation. Those who had any education（OR：1.9; 95% CI：1.1-3.2）,had blindness（OR：2.7; 95% CI：1.4-5.2）,and cataract（OR：2.1; 95% CI：1.0-4.3）as a cause of unilateral VI were more like to seek eye care consultations. The most commonly reported reasons for not seeking eye care services were ＂do not have money for eye checkup＂ in 30.7% of the participants followed by ＂do not have a serious problem＂（30.0%）.CONCLUSION：A large proportion of rural population though noticed a change in their vision did not seek eye care due to financial and person-related reasons. Eye care service providers need to address these barriers to enhance the uptake of eye care services among those with unilateral VI.

Visual impairment with possible macular changes after a high dose of sildenafil in a healthy young woman

Dear Editor,Sildenafil citrate（Viagra;Pfizer Pharmaceuticals,New York,NY,USA）,a selective inhibitor of phosphodiesterase type 5（PDE-5）,is widely used for erectile dysfunction.Its clinical recommended dosage is 25 to 100 mg per day.

Changed trends of major causes of visual impairment in Sichuan,China from 1987 to 2006

AIM: To study the trends of major causes of visual impairment(VI) in adults in Sichuan,China and evaluate the effect of aging on the trends. ·METHODS: We used data from the National Sample Survey on Disabilities(NSSD) in Sichuan province conducted in 1987 and 2006. The age-adjusted prevalence of major causes of VI and the prevalence stratified by age in each cause were calculated and compared. The association between age and each cause of VI was also analyzed.·RESULTS: Retinal disease increased and became the second leading cause of VI in 2006 while blinding trachoma decreased markedly. Cataract and non-trachomatous corneal diseases were among the leading causes of VI in both years. We found associations between age and causes of VI,with age showing the strongest association with cataract and relatively lower associations with other causes. · CONCLUSION: In the last two decades,dramatic changes occurred in the major causes of VI with significantly increased retinal disease and decreased blinding trachoma. Aging of the population might be an important factor accounting for the changed trends of VI. Understanding the prevalence of VI,its major causes and trends over time can assist in prioritizing and developing effective interventional strategies and monitoring their impact.

An enhanced functional ability questionnaire(faVIQ) to measure the impact of rehabilitation services on the visually impaired

AIM: To develop a short,enhanced functional ability Quality of Vision(faVIQ) instrument based on previous questionnaires employing comprehensive modern statistical techniques to ensure the use of an appropriate response scale,items and scoring of the visual related difficulties experienced by patients with visual impairment. · METHODS: Items in current quality-of-life questionnaires for the visually impaired were refined by a multi-professional group and visually impaired focus groups. The resulting 76 items were completed by 293 visually impaired patients with stable vision on two occasions separated by a month. The faVIQ scores of 75 patients with no ocular pathology were compared to 75 age and gender matched patients with visual impairment. ·RESULTS: Rasch analysis reduced the faVIQ items to 27. Correlation to standard visual metrics was moderate(r =0.32-0.46) and to the NEI-VFQ was 0.48. The faVIQ was able to clearly discriminate between age and gender matched populations with no ocular pathology and visual impairment with an index of 0.983 and 95% sensitivity and 95% specificity using a cut off of 29.·CONCLUSION: The faVIQ allows sensitive assessment of quality-of-life in the visually impaired and should support studies which evaluate the effectiveness of low vision rehabilitation services.

Knowledge, attitudes and practices related to seeking medical eyecare services by adults with moderate-to-severe visual impairment in rural Yueqing, Wenzhou, China: a cross-sectional survey

AIM:To evaluate the knowledge,attitudes,and practices regarding eye-care seeking practices of visually impaired adults in a rural area Yueqing,and explore factors influencing their behavior.METHODS:A stratified sampling method was used to select 48 villages in Yueqing,from which 2400 people were selected to receive vision screenings conducted by oculists during a household visit.Those presenting visual acuity≥0.5 log MAR in either eye completed a self-designed questionnaire investigating their knowledge about medical eye-care seeking,attitudes about eye health and eye-careseeking behavior.RESULTS:Totally 165 people with moderate-to-severe visual impairment were identified(6.9%,165/2400),and 146 eligible participants were recruited(response rate:88.4%,mean age:68.6±15.0 y),among which 88(60.3%)were female.They had 82(56.2%)and 64(43.8%)monocular and binocular visual impairments respectively.A total of 67(45.9%)subjects demonstrated a high knowledge level about medical eye-care seeking and 88(60.3%)had self-rated poor vision,with 23(15%)receiving regular vision checks.The 105(71.9%)subjects had never been to hospital for an eye examination."No need"and"schedule conflicts"were the main reasons for not seeking eye care.Having extensive knowledge of medical eye-care seeking was positively associated with high education levels(OR=3.73,P=0.045)and negatively correlated with older age(OR=0.97,P=0.043).Both the self-perceived vision condition(OR=2.59,P=0.03)and regular vision check behavior(OR=6.50,P<0.01)were related with seeking eye care services.CONCLUSION:In rural Yueqing,intervention is required to increase public knowledge about seeking medical eye care among people with moderate-to-severe visual impairment,especially for the elderly and poorly education.Regular vision checks may be useful to promote their medical eye-care utilization.

Deep Learning Based Audio Assistive System for Visually Impaired People

Vision impairment is a latent problem that affects numerous people across the globe.Technological advancements,particularly the rise of computer processing abilities like Deep Learning(DL)models and emergence of wearables pave a way for assisting visually-impaired persons.The models developed earlier specifically for visually-impaired people work effectually on single object detection in unconstrained environment.But,in real-time scenarios,these systems are inconsistent in providing effective guidance for visually-impaired people.In addition to object detection,extra information about the location of objects in the scene is essential for visually-impaired people.Keeping this in mind,the current research work presents an Efficient Object Detection Model with Audio Assistive System(EODM-AAS)using DL-based YOLO v3 model for visually-impaired people.The aim of the research article is to construct a model that can provide a detailed description of the objects around visually-impaired people.The presented model involves a DL-based YOLO v3 model for multi-label object detection.Besides,the presented model determines the position of object in the scene and finally generates an audio signal to notify the visually-impaired people.In order to validate the detection performance of the presented method,a detailed simulation analysis was conducted on four datasets.The simulation results established that the presented model produces effectual outcome over existing methods.

Development of Mobile App to Support the Mobility of Visually Impaired People

In 2017,it was estimated that the number of persons of all ages visually affected would be two hundred and eighty-five million,of which thirty-nine million are blind.There are several innovative technical solutions available to facilitate the movement of these people.The next big challenge for technical people is to give cost-effective solutions.One of the challenges for people with visual impairments is navigating safely,recognizing obstacles,and moving freely between locations in unfamiliar environments.A new mobile application solution is developed,and the application can be installed in android mobile.The application will visualize the environment with portable cameras and persons with visual impairment directly to the environment.The designed system mainly uses the YOLO3 program to identify and locate the distance between the objects and the camera.Furthermore,it determines the direction of the object.Finally,the system will give the voice command to teach/inform the visually impaired people to navigate the environment.It is a novel work at the global level.The proposed approach is cost-effective and affordable to all strata of society.