-
Journal of Robotic Surgery Oct 2023Stereopsis may be an advantage of robotic surgery. Perceived robotic ergonomic advantages in visualisation include better exposure, three-dimensional vision, surgeon... (Review)
Review
Stereopsis may be an advantage of robotic surgery. Perceived robotic ergonomic advantages in visualisation include better exposure, three-dimensional vision, surgeon camera control, and line of sight screen location. Other ergonomic factors relating to visualisation include stereo-acuity, vergence-accommodation mismatch, visual-perception mismatch, visual-vestibular mismatch, visuospatial ability, visual fatigue, and visual feedback to compensate for lack of haptic feedback. Visual fatigue symptoms may be related to dry eye or accommodative/binocular vision stress. Digital eye strain can be measured by questionnaires and objective tests. Management options include treatment of dry eye, correction of refractive error, and management of accommodation and vergence anomalies. Experienced robotic surgeons can use visual cues like tissue deformation and surgical tool information as surrogates for haptic feedback.
Topics: Humans; Robotic Surgical Procedures; Asthenopia; Depth Perception; Accommodation, Ocular; Ergonomics
PubMed: 37204648
DOI: 10.1007/s11701-023-01618-7 -
Indian Journal of Ophthalmology Aug 2020Asthenopic and related symptoms are a major problem in school-going children. With the inception of computers and other gadgets for near work, the unseen problems... (Review)
Review
Asthenopic and related symptoms are a major problem in school-going children. With the inception of computers and other gadgets for near work, the unseen problems arising out of constant and continuous near work, are on the rise. Parents wander from pillar to post, seeking respite from their child's constant complaints from near work; but despite best spectacle correction and avoidance of excessive near work, the complaints continue. Studies have shown that the majority of these problems arise from defects in accommodation, even in a young child. Therefore, various aspects of accommodation deficiencies have to be studied clinically, detected, and treated to ameliorate the symptoms.
Topics: Accommodation, Ocular; Asthenopia; Child; Computers; Eyeglasses; Humans; Schools
PubMed: 32709767
DOI: 10.4103/ijo.IJO_1973_18 -
Clinical Optometry 2023Digital Eye Strain (DES) is a clinical syndrome manifested with visual disturbances and/or ophthalmic dysfunction related to the usage of screen-enabled digital... (Review)
Review
Digital Eye Strain (DES) is a clinical syndrome manifested with visual disturbances and/or ophthalmic dysfunction related to the usage of screen-enabled digital equipment. This term is gradually replacing the older term computer vision syndrome (CVS) that focused on the same symptoms found on personal computer users. DES is encountered more frequently during the past years due to the explosive increase in the usage of digital devices and subsequent increase in time in front of any screens. It presents with a series of atypical symptoms and signs stemming from asthenopia, dry eye syndrome, preexisting untreated vision issues and poor screen ergonomics. This review summarizes research data to date to determine whether the concept of DES has been conclusively defined and demarcated as a separate entity and if sufficient guidance is offered on professionals and the lay public. The maturity of the field, grouping of symptoms, examination techniques, treatment and prevention modalities are summarily presented.
PubMed: 36875935
DOI: 10.2147/OPTO.S389114 -
Cortex; a Journal Devoted To the Study... Jun 2021Prosopometamorphopsia is an extremely rare disorder of visual perception characterised by facial distortions. We here review 81 cases (eight new ones and 73 cases... (Review)
Review
Prosopometamorphopsia is an extremely rare disorder of visual perception characterised by facial distortions. We here review 81 cases (eight new ones and 73 cases published over the past century) to shed light on the perception of face gestalts. Our analysis indicates that the brain systems underlying the perception of face gestalts have genuine network properties, in the sense that they are widely disseminated and built such that spatially normal perception of faces can be maintained even when large parts of the network are compromised. We found that bilateral facial distortions were primarily associated with right-sided and bilateral occipital lesions, and unilateral facial distortions with lesions ipsilateral to the distorted hemifield and with the splenium of the corpus callosum. We also found tentative evidence for the involvement of the left frontal regions in the fusing of vertical hemi-images of faces, and of right parietal regions in the fusing of horizontal hemi-images. Evidence supporting the remarkable adaptability of the network comes from the relatively high recovery rates that we found, from the ipsilateral hemifield predominance of hemi-prosopometamorphopsia, and from a phenomenon called cerebral asthenopia (heightened visual fatigability) which points to the dynamic nature of compensatory mechanisms maintaining normal face perception, even in chronic cases of prosopometamorphopsia. Finally, our analysis suggests that specialised networks for the representation of face gestalts in familiar-versus-unfamiliar faces and for own-versus-other face may be present, although this is in need of further study.
Topics: Brain; Brain Mapping; Corpus Callosum; Facial Recognition; Humans; Magnetic Resonance Imaging; Pattern Recognition, Visual; Visual Perception
PubMed: 33865569
DOI: 10.1016/j.cortex.2021.03.001 -
Journal of Ophthalmic & Vision Research 2019To determine the prevalence of asthenopia and its associated factors in a sample of university students in Iran. (Review)
Review
PURPOSE
To determine the prevalence of asthenopia and its associated factors in a sample of university students in Iran.
METHODS
In this cross-sectional study, participants were selected using multistage cluster sampling. Presence of at least one of the 10 symptoms-foreign body sensation, diplopia, blurred vision, eye swelling, dry eye, eye pain, difficulty in sustaining visual operations, decreased visual acuity, tearing, and photophobia-was considered as asthenopia. Ocular examinations, including uncorrected/corrected visual acuity measurement, objective/subjective refraction, cover test, amplitude of accommodation (AA), and near point of convergence (NPC) were performed.
RESULTS
Of the 1,462 students (mean age: 22.8 3.1 years), 73% were women. The age- and gender-standardized prevalence was 70.9% (95% confidence interval [CI]: 68.3-73.5), 39.8% (95% CI: 36.4-43.1), and 19.7% (95% CI: 16.0-23.3) based on the presence of at least one, two, and three symptoms, respectively. The prevalence was significantly higher in females ( = 0.048), hyperopic students ( 0.001), and astigmatic participants ( 0.001). The mean AA and NPC were 9.7 2.6 D and 10.2 4.2 D ( = 0.008) and 7.0 2.1 cm and 7.7 3.9 cm ( 0.001) in participants with and without asthenopia, respectively. Multiple regression model revealed age (28-29 years), astigmatism, and NPC as independent associated factors (odds ratios: 3.51, 1.61, and 0.91, respectively).
CONCLUSION
This study shows relatively high prevalence of asthenopia in university students. Demographic factors and visual system disorders are important risk factors and timely correction of conditions may lead to decreased asthenopia.
PubMed: 31875103
DOI: 10.18502/jovr.v14i4.5455 -
Clinical Optometry 2020Accommodative insufficiency (AI), defined as the inability to stimulate accommodation in pre-presbyopic individuals, has gained much attention over recent years. Despite... (Review)
Review
PURPOSE
Accommodative insufficiency (AI), defined as the inability to stimulate accommodation in pre-presbyopic individuals, has gained much attention over recent years. Despite the enormity of the available information, there is a significant lack of clarity regarding the criteria for definition, methodology adopted for testing and diagnosis, and the varied prevalence across the globe. This review aims to gather evidence that is pertinent to the prevalence, impact and efficacy of available treatment options for AI.
METHODS
PubMed, Google Scholar and Cochrane Collaboration search engines were used with the keywords prevalence, accommodative insufficiency, symptoms, plus lens, vision therapy and treatment. Peer-reviewed articles published between 1992 and 2019 were included in the review. After reviewing the studies for study methodology and robustness, 83 articles were chosen for this literature review.
RESULTS
The prevalence of AI ranges between <1.00% and 61.6% across studies. The prevalence shows considerable variation across ethnicities and age groups. There is significant variation in the study methodology, diagnostic criteria and number of tests performed to arrive at the diagnosis. Not many studies have explored the prevalence beyond 20 years of age. The prevalence of AI is high among children with special needs. There is no high-quality evidence regarding the standard treatment protocol for AI. Both vision therapy and low plus lenses have shown efficacy in independent studies, and no studies have compared these two treatment options.
CONCLUSION
The understanding of AI prevalence is currently limited owing to the lack of a standard set of diagnostic criteria and wide variations in the study methodology. There is a lack of high-quality evidence suggesting the best possible treatment for AI. The current gaps in the literature have been identified and future scope for exploration is elucidated.
PubMed: 32982529
DOI: 10.2147/OPTO.S224216 -
Journal of Clinical Medicine Nov 2022Purpose: To analyze the correlation between eye movements and asthenopia so as to explore the possibility of using eye-tracking techniques for objective assessment of...
Purpose: To analyze the correlation between eye movements and asthenopia so as to explore the possibility of using eye-tracking techniques for objective assessment of asthenopia. Methods: This prospective observational study used the computer visual syndrome questionnaire to assess the severity of asthenopia in 93 enrolled college students (age 20−30) who complained about asthenopia. Binocular accommodation and eye movements during the reading task were also examined. The correlations between questionnaire score and accommodation examination results and eye movement parameters were analyzed. Differences in eye movement parameters between the first and last reading paragraphs were compared. The trends in eye movement changes over time were observed. Results: About 81.7% of the subjects suffered from computer visual syndrome. Computer visual syndrome questionnaire total score was positively correlated with positive relative accommodation (p < 0.05). In the first reading paragraph, double vision was positively correlated with unknown saccades (all p < 0.05). Difficulty focusing at close range was positively correlated with total fixation duration, total visit duration, and reading speed (all p < 0.05). Feeling that sight was worsening was positively correlated with regressive saccades (p < 0.05). However, visual impairment symptoms were not significantly correlated with any accommodative function. In a total 20 min reading, significantly reduced eye movement parameters were: total fixation duration, fixation count, total visit duration, visit count, fixation duration mean, and reading speed (all p < 0.01). The eye movement parameters that were significantly increased were: visit duration mean and unknown saccades (all p < 0.001). Conclusion: Eye tracking could be used as an effective assessment for asthenopia. Among the various eye movement parameters, a decrease in fixation duration and counts may be one of the potential indicators related to asthenopia.
PubMed: 36498619
DOI: 10.3390/jcm11237043 -
Clinical & Experimental Optometry Nov 2019Aniseikonia is a difference in the perceived size or shape of images between eyes, and can arise from a variety of physiological, neurological, retinal, and optical... (Review)
Review
Aniseikonia is a difference in the perceived size or shape of images between eyes, and can arise from a variety of physiological, neurological, retinal, and optical causes. Aniseikonia is associated with anisometropia, as both anisometropia itself and the optical correction for anisometropia can cause aniseikonia. Image size differences above one to three per cent can be clinically symptomatic. Common symptoms include asthenopia, headache and diplopia in vertical gaze. Size differences of three and more impair binocular visual functions such as binocular summation and stereopsis. Above five per cent of aniseikonia, binocular inhibition or suppression tend to occur to prevent diplopia and confusion. Aniseikonia can be measured using a range of techniques and can be corrected or reduced by prescribing contact lenses or specially designed spectacle lenses. Subjective testing of aniseikonia is the only way to accurately measure the overall perceived amount of aniseikonia. However, currently it is not routinely assessed in most clinical settings. At least two-thirds of patients with amblyopia have anisometropia, thus we may expect aniseikonia to be common in patients with anisometropic amblyopia. However, aniseikonia may not be experienced by the patient under normal binocular viewing conditions if the image from the amblyopic eye is of poor quality or is too strongly suppressed for image size differences to be recognised. This lack of binocular simultaneous perception in amblyopia may also prevent the measurement of aniseikonia, as most common techniques require direct comparisons of images seen by each eye. Current guidelines for the treatment of amblyopia advocate full correction of anisometropia to equalise image clarity, but do not address aniseikonia. Significant image size differences between eyes may lead to suppression and abnormal binocular adaptations. It is possible that correcting anisometropia and aniseikonia simultaneously, particularly at the initial diagnosis of anisometropia, would reduce the need to develop suppression and improve treatment outcomes for anisometropic amblyopia.
Topics: Amblyopia; Aniseikonia; Anisometropia; Humans
PubMed: 30791133
DOI: 10.1111/cxo.12881 -
Nutrients Sep 2022Digital eye strain is a complex, multifactorial condition that can be caused by excessive screen time exposure to various electronic devices such as smartphones,... (Review)
Review
Digital eye strain is a complex, multifactorial condition that can be caused by excessive screen time exposure to various electronic devices such as smartphones, tablets, e-readers, and computers. Current literature suggests oxidative damage concomitant with a chronic pro-inflammatory state represent significant etiopathogenic mechanisms. The present review aims to discuss the potential dietary role for micronutrients with nutraceutical properties to ameliorate various ocular and vision-related symptoms associated with digital eye strain. For ocular surface dysfunction, enhanced anti-inflammatory benefits with omega-3 polyunsaturated fatty acids have been well documented for treatment of dry eye disease. The anti-oxidative and immunosuppressive properties of anthocyanin phytochemicals may also confer protective effects against visually induced cognitive stress and digital asthenopia. Meanwhile, nutraceutical strategies involving xanthophyll macular carotenoids demonstrate enhanced cognitive functioning and overall visual performance that aids digital eye strain. Collectively, preliminary findings seem to offer a strong line of evidence to substantiate the need for additional randomized controlled trials aimed at treating digital eye strain with adjunctive nutraceutical strategies. Further RCT and comparisons on commercially available nutritional supplements are needed to quantify the clinical benefits.
Topics: Anthocyanins; Asthenopia; Dry Eye Syndromes; Fatty Acids, Omega-3; Humans; Micronutrients; Xanthophylls
PubMed: 36235656
DOI: 10.3390/nu14194005 -
Journal of Family Medicine and Primary... Aug 2020Asthenopia or eye strain is one of the major medical problems that students face during their academic years.
BACKGROUND
Asthenopia or eye strain is one of the major medical problems that students face during their academic years.
OBJECTIVES
The aim of this study is to determine the prevalence of asthenopia among a sample of university students attending various majors and to identify the risk factors for its development.
METHODS
This is a cross sectional study conducted on students attending various faculties at the American University of Beirut during the spring semester of 2019. Students were asked to fill a self-administered anonymous questionnaire that inquired about demographics, use of digital devices, symptoms of asthenopia, possible risk factors and protective measures. A bivariate analysis was performed to correlate asthenopia with the different variables. A multivariate analysis was then conducted to determine the extent of contribution of the different variables to asthenopia after controlling for confounding variables.
RESULTS
The prevalence of asthenopia was found to be 67.8% with blurred vision being the most reported symptom (27.0%). A bivariate analysis was used to assess the association between asthenopia and the following variables: demographics, digital device use, reasons for using digital devices, and preventive methods. Age, being a continuous variable, was analyzed using an independent t- test. For the variables that were found to be have a p-value < 0.2, a multiple logistic regression was performed. Old age was found to be a protective factor for asthenopia, with 0.693 times reduction in asthenopia for every increase in year of age. Using the device for communication for less than four hours (=0.012), using the device for less than four hours per day (=0.000) and pattern of using the device for less than three years (=0.023) were significant in being negatively associated with asthenopia. As for preventative measures that protect users from digital eyestrain, we found that using eye drops (=0.004; OR=0.375) and taking regular breaks (=0.000; OR= 0.399) were protective factors whereas using adjustable screens was a risk factor (=0.000; OR=3.083).
CONCLUSION
Asthenopia was found to be of non-negligible prevalence among this sample of university students. The results of this study highlight the importance of establishing awareness campaigns and encourage the introduction of targeted screenings for asthenopia among college students.
PubMed: 33110788
DOI: 10.4103/jfmpc.jfmpc_340_20