Measuring Visual Discomfort in College Students

The Relationship between Anxiety, Visual Function, and Symptomatology in University Students

Mental health concerns have emerged at the university level, with the psychological well-being of students being increasingly affected. This cross-sectional study investigated the proportion of university students having anxiety, and its effects on their visual function and symptomatology. We included 41 students (26.1 ± 4.8 years), and their visual function was assessed through several tests to produce a general visual performance index (VPI). The visual symptomatology was studied using the Conlon Visual Discomfort Survey and the Quality of Vision (QoV) questionnaire. The students were classified into two groups according to the Generalized Anxiety Disorder Screener (GAD-7) test ("no anxiety" and "anxiety" groups). The visual function evaluation indicated significantly worse VPI in the anxiety group (p = 0.047). These students also showed significantly higher scores in the Conlon survey (p = 0.004) and two subscales of the QoV questionnaire: symptom severity (p = 0.041) and symptom bothersomeness (p = 0.013). Moreover, the multiple linear regression model showed a significant association between visual discomfort according to the Conlon questionnaire and the level of anxiety (r = 0.405; R2 = 0.164; B = 0.405; p = 0.012). It is important to study the influence of psychological factors on vision, not only for refractive error, but also for binocular and accommodative disorders.

Visual discomfort and contact lens wear: A review

The purpose of this manuscript is to describe how vision influences contact lens discomfort and review the evidence supporting the hypothesis that contact lens discomfort can be caused by vision and vision-related disorders. Contact lens discomfort is a misunderstood and difficult to manage clinical condition. Most treatments and strategies aimed at alleviating discomfort focus on optimizing the contact lens fit and its relationship with the ocular surface, but these strategies commonly fail at relieving discomfort symptoms. Many vision and vision-related disorders share symptoms with those reported by uncomfortable contact lens wearers. This paper will review evidence and literature that describes how these vision and vision-related disorders may influence comfort in contact lens wearers. Acknowledging how vision influences contact lens discomfort will improve future research intended to better understand the condition, allow for more effective clinical management, and reduce rates of discontinuation.

An Explainable Student Fatigue Monitoring Module with Joint Facial Representation

Online fatigue estimation is, inevitably, in demand as fatigue can impair the health of college students and lower the quality of higher education. Therefore, it is essential to monitor college students' fatigue to diminish its adverse effects on the health and academic performance of college students. However, former studies on student fatigue monitoring are mainly survey-based with offline analysis, instead of using constant fatigue monitoring. Hence, we proposed an explainable student fatigue estimation model based on joint facial representation. This model includes two modules: a spacial-temporal symptom classification module and a data-experience joint status inferring module. The first module tracks a student's face and generates spatial-temporal features using a deep convolutional neural network (CNN) for the relevant drivers of abnormal symptom classification; the second module infers a student's status with symptom classification results with maximum a posteriori (MAP) under the data-experience joint constraints. The model was trained on the benchmark NTHU Driver Drowsiness Detection (NTHU-DDD) dataset and tested on an Online Student Fatigue Monitoring (OSFM) dataset. Our method outperformed the other methods with an accuracy rate of 94.47% under the same training-testing setting. The results were significant for real-time monitoring of students' fatigue states during online classes and could also provide practical strategies for in-person education.

Visual Sensitivity in Complex Regional Pain Syndrome and Fibromyalgia: An Online Study

Perceptual anomalies can provide insights into underlying pathologies even when they are not the main symptom of many clinical conditions. Complex regional pain syndrome (CRPS) and fibromyalgia are chronic pain conditions associated with changes in the central nervous system, possibly leading to enhanced visual sensitivity. It is unclear whether this occurs more than for people with other types of pain. We examined visual sensitivity elicited by different stimuli and in daily life, through an online study of people with CRPS (n = 57), fibromyalgia (n = 74), other pain (n = 50), and no pain (n = 89). Respondents rated changes in pain, discomfort, or distress from viewing patterns with different spatial frequencies (lower-order visual processing), and reversible figures (bistable images; higher-order visual processing). We assessed visual sensitivity in daily life using the Leiden Visual Sensitivity Scale and Visual Discomfort Scale. Respondents with CRPS or fibromyalgia reported more visual discomfort than pain-related and pain-free controls while viewing striped patterns and a circle, with no effect of spatial frequency. They reported more pain while viewing a nonreversible square, but not reversible figures (Necker Cube, Duck/Rabbit). Finally, they reported more daily visual sensitivity than pain-related and pain-free controls. Suppressing visual cortical activity might benefit people with CRPS or fibromyalgia.

Does coexisting accommodative dysfunction impact clinical convergence measures, symptoms and treatment success for symptomatic convergence insufficiency in children?

PURPOSE

To determine whether coexisting accommodative dysfunction in children with symptomatic convergence insufficiency (CI) impacts presenting clinical convergence measures, symptoms and treatment success for CI.

METHODS

Secondary data analyses of monocular accommodative amplitude (AA; push-up method), monocular accommodative facility (AF; ±2.00 D lens flippers) and symptoms (CI Symptom Survey [CISS]) in children with symptomatic CI from the Convergence Insufficiency Treatment Trial (N = 218) and CITT-Attention and Reading Trial (N = 302) were conducted. Decreased AA was defined as more than 2D below the minimum expected amplitude for age (15 - ¼ age); those with AA < 5 D were excluded. Decreased AF was defined as <6 cycles per minute. Mean near point of convergence (NPC), near positive fusional vergence (PFV) and symptoms (CISS) were compared between those with and without accommodative dysfunction using analysis of variance and independent samples t-testing. Logistic regression was used to compare the effect of baseline accommodative function on treatment success [defined using a composite of improvements in: (1) clinical convergence measures and symptoms (NPC, PFV and CISS scores) or (2) solely convergence measures (NPC and PFV)].

RESULTS

Accommodative dysfunction was common in children with symptomatic CI (55% had decreased AA; 34% had decreased AF). NPC was significantly worse in those with decreased AA (mean difference = 6.1 cm; p < 0.001). Mean baseline CISS scores were slightly worse in children with coexisting accommodative dysfunction (decreased AA or AF) (30.2 points) than those with normal accommodation (26.9 points) (mean difference = 3.3 points; p < 0.001). Neither baseline accommodative function (p ≥ 0.12 for all) nor interaction of baseline accommodative function and treatment (p ≥ 0.50) were related to treatment success based on the two composite outcomes.

CONCLUSIONS

A coexisting accommodative dysfunction in children with symptomatic CI is associated with worse NPC, but it does not impact the severity of symptoms in a clinically meaningful way. Concurrent accommodative dysfunction does not impact treatment response for CI.

Validation of the Leiden Visual Sensitivity Scale and Visual Discomfort Scale in Chronic Pain Conditions

Discomfort provoked by normally innocuous visual stimuli has been reported by people with chronic pain. Visual discomfort may be higher in pain conditions in which central sensitization is implicated, such as Complex Regional Pain Syndrome (CRPS) and fibromyalgia. In an online study, we validated the Leiden Visual Sensitivity Scale (L-VISS) and Visual Discomfort Scale (VDS) in people with CRPS (n = 57), fibromyalgia (n = 75), and general chronic pain (n = 53); investigated whether these groups and pain-free controls (n = 125) differed in visual discomfort; and evaluated the effect of age. The L-VISS and VDS had good internal consistency. Both scales were positively related with experimentally induced visual distortions for mid-spatial frequency striped patterns, suggesting good construct validity. The scales were positively related with each other, and dissociated between the pain and pain-free groups in similar ways, suggesting good construct validity. There was no relationship between age and L-VISS scores and a small negative relationship between age and VDS scores. Visual discomfort was highest in the fibromyalgia group, followed by the CRPS group. This research confirms the utility of the L-VISS and VDS for measuring visual sensitivity in chronic pain and adds to evidence that central sensitization is an important mechanism of visual discomfort.

Ocular symptoms associated with digital device use in contact lens and non-contact lens groups

PURPOSE

Previous reports indicate that "eye fatigue" occurs in roughly 60 % of the adult population using digital devices and may negatively impact quality of life. However, the construct of eye fatigue remains poorly understood. The goal of this study was to quantify the relationship among symptoms most frequently associated with eye fatigue in those using digital devices.

METHODS

Six hundred and two soft contact lens (SCL) wearers and 127 non-contact lens (non-CL) wearers who reported using digital devices at least 4 hours per day completed a questionnaire assessing the frequency and severity of ten symptoms commonly associated with digital device-related eye fatigue. Subjective ratings were made separately for each symptom using unipolar, five-point Likert scales.

RESULTS

From the initial pool of respondents, 89 % of the SCL wearers reported experiencing eye fatigue more than once per month, while over 60 % reported more than once per week. Notably, eye fatigue frequency did not differ between the soft contact and non-contact lens groups. Although eye strain/pain, dryness, and tired eyes were the most frequently endorsed symptoms by both groups, only dryness and eye irritation were significant factors that discriminated the SCL from the non-CL wearers on the basis of frequency and severity. Principal component analysis indicated that eye strain/pain, soreness, tired eyes, and headaches may comprise a "primary sensations" factor, whereas burning, eye irritation, tearing and dryness comprise a "secondary or surface sensations" factor, and blurred/double vision and words move/float comprise a "visual sensations" factor. Confirmatory factor analysis (CFA) of frequency and severity ratings for SCL wearers yielded excellent fits (RMSEA = 0.046 and 0.050, respectively) with construct reliabilities ranging from 0.729 to 0.824.

CONCLUSION

Frequent and severe eye fatigue is highly prevalent among both soft contact lens and non-contact lens wearers. Those utilizing SCL do not experience symptoms at higher frequency or severity. Key descriptors of digital eye fatigue have been identified and may then be used to help identify and evaluate specific causative, palliative, or ameliorating factors.

Fruit and vegetable consumption and its relation to risk of asthenopia among Chinese college students

AIM

To investigate the associations between fruit and vegetable consumption and risk of asthenopia among Chinese college students.

METHODS

A total of 1022 students were selected from five universities by a multi-stage stratified cluster sampling method. They were surveyed via a self-administered questionnaire including socio-demographic features, dietary and lifestyle habits, eye-related symptoms, eye care habits and history of diseases. Ascertainment of asthenopia was based on participants' subjectively reported symptoms. The associations between fruit and vegetable intake with asthenopia risk were assessed using multivariate logistic regression analysis.

RESULTS

There were no significant associations between total fruit and vegetable, total vegetable, or fruit and the risk of asthenopia. Higher intake of dark-green leafy vegetable was likely to be inversely associated with asthenopia risk [odd ratio (OR): 0.60; 95%CI: 0.37-0.97; P_trend=0.21] after controlling for nondietary and dietary risk factors. Stratified analysis showed that the inverse association between dark-green leafy vegetable intake and asthenopia risk was limited to participants with suboptimal eyesight (OR: 0.45; 95%CI: 0.25-0.82; P_trend=0.05), wearing glasses (OR: 0.35; 95%CI: 0.17-0.72; P_trend=0.03) or using computer ≥3h/d (OR: 0.48; 95%CI: 0.25-0.93; P_trend=0.08).

CONCLUSION

A higher consumption of dark-green leafy vegetable is associated with a lower asthenopia risk among college students with suboptimal eyesight and poor eye care habits.

Measuring mental workload: ocular astigmatism aberration as a novel objective index

This study assessed the effect of two perceptually matched mental tasks with different levels of mental demand on ocular aberrations in a group of young adults. We measured ocular aberration with a wavefront sensor, and total, internal and corneal RMS (root mean square) aberrations were calculated from Zernike coefficients, considering natural and scaled pupils (5, 4.5, and 4 mm). We found that total, internal and corneal astigmatism RMS showed significant differences between mental tasks with natural pupils (p < .05), and this effect was maintained with 5 mm scaled pupils (total RMS astigmatism, p < .05). Consistently, pupil size, intraocular pressure, perceived mental load and cognitive performance were influenced by the level of mental complexity (p < .05 for all). The findings suggest that ocular astigmatism aberration, mediated by intraocular pressure, could be an objective, valid reliable index to evaluate the impact of cognitive processing in conjunction with others physiological markers in real world contexts. Practitioner Summary: The search continues for a valid, reliable, convenient method of measuring mental workload. In this study we found ocular astigmatism aberration is sensitive to the cumulative effect of mental effort. It shows promise of being a novel ocular index which may help to assess mental workload in real situations.

Development of the Japanese version of the Visual Discomfort Scale

BACKGROUND

Visual stimuli, such as stripes and texts, can induce "visual discomfort" including perceptual and somatic symptoms. Individuals reporting high levels of visual discomfort might experience migraine headache and may have reduced reading efficiency due to visual perceptual difficulties. This study aimed to develop and validate the Japanese version of the Visual Discomfort Scale, which measures proneness to visual discomfort.

METHODS AND RESULTS

In Survey 1, 428 adults completed the Japanese version and a questionnaire assessing migraine morbidity. Rasch analysis revealed that the Japanese version is a unidimensional scale with a high amount of unexplained variance due to random noise rather than another dimension, and has high person and item reliabilities. Participants with migraine exhibited high scores in the Japanese version, indicating the construct validity of the scale. Survey 2 with 118 adults revealed a strong test-retest correlation for the Japanese version, indicating the stability of the scale.

CONCLUSION

The Japanese version of the Visual Discomfort Scale is a sufficiently reliable and valid scale for assessing visual discomfort, although its unidimensionality leaves room for further improvements.

An Overwhelming Desire to Be Blind: Similarities and Differences between Body Integrity Identity Disorder and the Wish for Blindness

Background

The urge to be permanently blind is an extremely rare mental health disturbance. The underlying cause of this desire has not been determined yet, and it is uncertain whether the wish for blindness is a condition that can be included in the context of body integrity identity disorder, a condition where people feel an overwhelming need to be disabled, in many cases by amputation of a limb or through paralysis.

Objective

The aim of this study is to test the hypothesis that people with a desire for blindness suffer from a greater degree of visual stress in daily activities than people in a healthy visual control group.

Method

We created a Likert scale questionnaire to measure visual stress, covering a wide range of everyday situations. The wish for blindness is extremely rare and worldwide only 5 people with an urge to be blind were found to participate in the study (4 female, 1 male). In addition, a control group of 35 (28 female, 7 male) visually healthy people was investigated. Questions addressing issues that may be experienced by participants with a desire to be blind were integrated into the questionnaire.

Results

The hypothesis that people with a desire for blindness suffer from a significantly higher visual overload in activities of daily living than visually healthy subjects was confirmed; the significance of visual stress between these groups was p < 0.01. In addition, an interview with the 5 affected participants supported the causal role of visual overload.

Conclusions

The desire for blindness seems to originate from visual overload caused by either ophthalmologic or organic brain disturbances. In addition, psychological reasons such as certain personal character traits may play an active role in developing, maintaining, and reinforcing one's desire to be blind.

Accommodative changes after SMILE for moderate to high myopia correction

Background

To investigate accommodative response and accommodative lag changes after femtosecond laser small incision lenticule extraction (SMILE) for moderate to high myopia correction.

Methods

A total of 32 eyes of 32 patients with no strabismus who underwent SMILE were enrolled in this prospective clinical study. The accommodative response was obtained viewing monocularly with spherical equivalent refractive error corrected, using an open-field autorefractor at different stimulus levels (2.00D, 2.50D, 3.00D, 4.00D and 5.00D) for the right eye before a standard SMILE surgery and at 1-month follow-up after surgery.

Results

The mean age of the patients were 23.34 ± 2.90 years and the mean preoperative manifest refraction spherical equivalent was −5.74 ± 1.98 diopters. Significant differences were detected in both preoperative and postoperative accommodative responses to different stimulus levels (P < 0.001). Multiple linear regression model analysis revealed preoperative manifest refractive spherical equivalent (P = 0.006) and preoperative accommodative lag (P = 0.04) showed a significant impact on postoperative accommodative lag.

Conclusions

This is the first report of accommodative changes after SMILE. Our preliminary results showed that a decrease in postoperative accommodative lag that might be related to the relief of the visual discomfort symptom.

Evaluation of visual stress symptoms in age-matched dyslexic, Meares-Irlen syndrome and normal adults

AIM

To examine the prevalence of dyslexia and Meares-Irlen syndrome (MIS) among female students and determine their level of visual stress in comparison with normal subjects.

METHODS

A random sample of 450 female medical students of King Saud University Riyadh (age range, 18-30y) responded to a wide range of questions designed to accomplish the aims of this study. The detailed questionnaire consisted of 54 questions with 12 questions enquiring on ocular history and demography of participants while 42 questions were on visual symptoms. Items were categorized into critical and non-critical questions (CQ and NCQ) and were rated on four point Likert scale. Based on the responses obtained, the subjects were grouped into normal (control), dyslexic with or without MIS (Group 1) and subjects with MIS only (Group 2). Responses were analysed as averages and mean scores were calculated and compared between groups using one way analysis of variance to evaluate total visual stress score (TVSS=NCQ+CQ), critical and non-critical visual stress scores. The relationship between categorical variables such as age, handedness and condition were assessed with Chi-square test.

RESULTS

The completion rate was 97.6% and majority of the respondents (92%) were normal readers, 2% dyslexic and 6% had MIS. They were age-matched. More than half of the participants had visited an eye care practitioner in the last 2y. About 13% were recommended eye exercises and one participant experienced pattern glare. Hand preference was not associated with any condition but Group 1 subjects (3/9, 33%) were significantly more likely to be diagnosed of lazy eye than Group 2 (2/27, 7%) and control (27/414, 7%) subjects. The mean±SD of TVSS responses were 63±14 and it was 44±9 for CQ and 19±5 for NCQ. Responses from all three variables were normally distributed but the CQ responses were on the average more positive (82%) in Group 2 and less positive (46%) in Group 1 than control. With NCQ, the responses were equally less positive in Group 1 and 2 than control. Group 2 subjects showed significantly higher TVSS (P=0.002), NCQ (P=0.006) and CQ (P=0.008) visual stress scores than control but no difference between Group 1 and control subjects, was observed for all scores (P>0.05, for all comparisons).

CONCLUSION

The prevalence of dyslexia and MIS among Saudi female students was 2% and 6%, respectively. Critical questions performed best for assessing visual stress symptoms in dyslexic and MIS subjects. Generally, students with MIS were more sensitive to visual stress than normal students but dyslexics were more likely to present with a lazy eye than MIS and normal readers.

Accommodative and binocular dysfunctions: prevalence in a randomised sample of university students

BACKGROUND

The aim was to analyse the prevalence of symptomatic accommodative and non-strabismic binocular dysfunctions in a randomised population of university subjects.

METHODS

A cross-sectional study was conducted with a randomised sample of 175 university students aged between 18 and 35 years. All subjects were given a visual examination in which their symptoms were recorded, as well as performing objective and subjective refractive examinations and accommodative and binocular tests. Each subject was tested for the presence of uncorrected refractive error. Accommodative dysfunctions (AD) and binocular dysfunctions (BD) were diagnosed according to the number of clinical signs associated with each disorder, considering the signs that could be associated with each dysfunction as fundamental or complementary. An accommodative or binocular dysfunction was diagnosed when the subjects met two conditions: presenting with any kind of visual symptom in their clinical history and presenting the fundamental sign associated with each dysfunction as well as two or more complementary signs. Those subjects who presented with only an uncorrected refractive error were considered within the group called refractive dysfunction (RD).

RESULTS

The overall prevalence of accommodative and/or binocular dysfunctions was 13.15 per cent and for refractive dysfunction it was 45.14 per cent. Accommodative dysfunctions were present in 2.29 per cent of the population, binocular dysfunctions were observed in eight per cent and accommodative dysfunctions together were found in 2.86 per cent of the university students. Within the accommodative and binocular disorders, the most prevalent dysfunctions were convergence insufficiency, with a prevalence of 3.43 per cent and convergence excess and accommodation excess, both with a prevalence of 2.29 per cent.

CONCLUSION

Binocular dysfunctions were more prevalent than accommodative dysfunctions or accommodative and binocular dysfunctions together in a randomised population of university students.

Characterization of Visual Symptomatology Associated with Refractive, Accommodative, and Binocular Anomalies

Purpose. To characterize the symptomatology of refractive, accommodative, and nonstrabismic binocular dysfunctions and to assess the association between dysfunctions and symptoms. Methods. 175 randomised university students were examined. Subjects were given a subjective visual examination with accommodative and binocular tests, evaluating their symptomatology. Accommodative and binocular dysfunctions (AD, BD) were diagnosed according to the number of existing clinical signs: suspect AD or BD (one fundamental clinical sign), high suspect (one fundamental + 1 complementary clinical sign), and definite (one fundamental + 2 or more complementary clinical signs). A logistic regression was conducted in order to determine whether there was an association between dysfunctions and symptoms. Results. 78 subjects (44.6%) reported any kind of symptoms which were grouped into 18 categories, with “visual fatigue” being the most frequent (20% of the overall complaints). Logistic regression adjusted by the presence of an uncorrected refractive error showed no association between any grade of AD and symptoms. Subjects with BD had more likelihood of having symptoms than without dysfunction group (OR = 3.35), being greater when only definite BD were considered (OR = 8.79). Conclusions. An uncorrected refractive error is a confusion factor when considering AD symptomatology. For BD, the more the number of clinical signs used the greater the likelihood suffering symptoms.

Can Binocular Vision Disorders Contribute to Contact Lens Discomfort?

PURPOSE

To determine the relationship between binocular vision (BV) disorder and dry eye symptoms and the frequency of BV disorders in subjects with contact lens-induced dry eye symptoms.

METHODS

Subjects recruited for a larger dry eye study (n = 104) completed the Ocular Surface Disease Index (OSDI) and Convergence Insufficiency Symptom Survey (CISS) to determine if symptoms assessed on these two surveys were related. Also, myopic soft contact lens wearers (n = 29) with self-reported dry eye symptoms were recruited. Subjects completed the OSDI and CISS to assess severity of dry eye and BV disorder symptoms. Basic BV and dry eye testing was performed on each subject.

RESULTS

Severity of symptoms assessed on the OSDI and CISS was found to be significantly correlated in the larger subject group (ρ = 0.68, p = 0.0001). This significant correlation warranted further investigation of both symptoms and clinical signs. In the group of myopic soft contact lens wearers, 48.3% had a BV disorder. This proportion appeared to be higher than previously reported prevalence estimates of BV disorders. Accommodative lag greater than or equal to 1.00 diopter was the most common BV disorder sign encountered (48.3%), and pseudo-convergence insufficiency was the most common BV disorder (31.0%).

CONCLUSIONS

Symptoms related to dry eye and BV disorders overlap. Subjects with symptoms of discomfort while wearing soft contact lenses may be experiencing a concurrent or stand-alone BV disorder. Accommodative insufficiency and pseudo-convergence insufficiency were common in the sample of myopic soft contact lens wearers. Clinicians should screen symptomatic contact lens-induced dry eye patients for BV disorders. Dry eye studies should assess basic BV function.

Lexical decisions in adults with low and high susceptibility to pattern-related visual stress: a preliminary investigation

Pattern-related visual stress (PRVS) is a form of sensory hypersensitivity that some people experience when viewing high contrast repeating patterns, notably alternating dark and light stripes. Those susceptible to PRVS typically have a strong aversion to such stimuli, and this is often accompanied by experiences of visual discomfort and disturbance. The patterns most likely to elicit symptoms of PRVS have a square-wave grating configuration of spatial frequency ~3 cycles/degree. Such stimuli are characteristic of printed text in which lines of words and the spaces between them present a high contrast grating-like stimulus. Consequently, much printed reading material has the potential to elicit PRVS that may impair reading performance, and this problem appears to be common in individuals with reading difficulties including dyslexia. However, the manner in which PRVS affects reading ability is unknown. One possibility is that the early sensory visual stress may interfere with the later cognitive word recognition stage of the reading process, resulting in reading performance that is slower and/or less accurate. To explore the association of PRVS with word recognition ability, lexical decision performance (speed and accuracy) to words and pronounceable non-words was measured in two groups of adults, having low and high susceptibility to PRVS. Results showed that lexical decisions were generally faster but less accurate in high-PRVS, and also that high-PRVS participants made decisions significantly faster for words than for non-words, revealing a strong lexicality effect that was not present in low-PRVS. These findings are novel and, as yet, unconfirmed by other studies.

Identifying visual stress during a routine eye examination

PURPOSE

To investigate whether the clinical tests used in routine eye examinations can identify adults whose reading rate increases with their preferred coloured overlay(s).

METHODS

Routine optometric tests were used to measure 73 undergraduate students' refractive error, visual acuity, stereo-acuity, amplitude of accommodation, near point of convergence, associated heterophoria at near, colour vision and ocular motility. Participants chose an overlay or combination of overlays with colour optimal for clarity, and completed the Wilkins Rate of Reading Test with and without an overlay(s) of this colour.

RESULTS

Overall, there was a significant increase in reading speed with overlay (t(72)=-5.26, p<0.0005). Twenty-six participants (36%) increased their reading rate by >5% with their chosen coloured overlay(s). Ten participants (14%) had a reading speed increase of >10%. The increase in reading speed was not significantly associated with any clinical finding.

CONCLUSION

Tests which are completed in routine eye examinations did not identify those participants who benefitted from coloured overlays in terms of reading speed.

Symptomatology associated with accommodative and binocular vision anomalies

PURPOSE

To determine the symptoms associated with accommodative and non-strabismic binocular dysfunctions and to assess the methods used to obtain the subjects' symptoms.

METHODS

We conducted a scoping review of articles published between 1988 and 2012 that analysed any aspect of the symptomatology associated with accommodative and non-strabismic binocular dysfunctions. The literature search was performed in Medline (PubMed), CINAHL, PsycINFO and FRANCIS. A total of 657 articles were identified, and 56 met the inclusion criteria.

RESULTS

We found 267 different ways of naming the symptoms related to these anomalies, which we grouped into 34 symptom categories. Of the 56 studies, 35 employed questionnaires and 21 obtained the symptoms from clinical histories. We found 11 questionnaires, of which only 3 had been validated: the convergence insufficiency symptom survey (CISS V-15) and CIRS parent version, both specific for convergence insufficiency, and the Conlon survey, developed for visual anomalies in general. The most widely used questionnaire (21 studies) was the CISS V-15. Of the 34 categories of symptoms, the most frequently mentioned were: headache, blurred vision, diplopia, visual fatigue, and movement or flicker of words at near vision, which were fundamentally related to near vision and binocular anomalies.

CONCLUSIONS

There is a wide disparity of symptoms related to accommodative and binocular dysfunctions in the scientific literature, most of which are associated with near vision and binocular dysfunctions. The only psychometrically validated questionnaires that we found (n=3) were related to convergence insufficiency and to visual dysfunctions in general and there no specific questionnaires for other anomalies.

Measurement of visual sensitivity in migraine: Validation of two scales and correlation with visual cortex activation

Objective

The objectives of this article are to compare interictal and ictal visual sensitivity between migraine and controls using two published questionnaires, and to correlate responses with a physiologic measure of visual cortex activation.

Methods

Migraine with (MWA, n = 51) and without (MwoA, n = 45) aura and control individuals ( n = 45) were enrolled and underwent BOLD fMRI with a visual stimulus. The visual discomfort score (VDS) assessed interictal and the migraine photophobia score (MPS) assessed ictal visual sensitivity.

Result

VDS was significantly higher both in MWA and MwoA vs controls (both p < 0.0001). MPS was greater in MWA vs MwoA ( p = 0.008). Ictal and interictal visual sensitivity strongly correlated in MWA ( p = 0.004) but not MwoA patients ( p = 0.12). BOLD activation in visual cortex was greater in MWA vs controls (2.7% vs 2.3%, p = 0.003) but similar between MwoA and controls. Increasing VDS was associated with greater BOLD signal change in MWA ( p = 0.03) but not MwoA ( p = 0.65) or controls ( p = 0.53). MPS did not correlate with BOLD activation in either group.

Conclusion

Increased interictal visual sensitivity is present both in MWA and MwoA. However, the correlation with ictal visual sensitivity and with cortical hyper-responsivity varies between MWA and MwoA, suggesting underlying differences between groups.

Can chronic visual discomfort measures accurately predict acute symptoms?

PURPOSE

Several surveys exist to determine the severity and frequency of chronic symptoms related to visual discomfort. To our knowledge, there are no studies that investigate the potential of chronic visual discomfort ratings to predict acute discomfort symptoms that are experienced after tests of accommodation and vergence. We examined the ability of two measures of chronic visual discomfort symptoms to predict acute symptoms experienced.

METHODS

The Conlon et al. and the convergence insufficiency symptom surveys were administered to 40 participants to assess chronic visual discomfort symptoms. Two measures were used to assess acute symptoms. The first consisted of four Likert-scaled questions relating to comfort level during last test, visual distortions or movement, discomfort caused by overhead lights, and presence of headache symptoms. These questions were asked before and after binocular examination, and the scores were used to generate a postexamination symptom score. The second measure of acute symptoms consisted of participants rating their general discomfort on a four-point Likert scale after each binocular test, and the ratings were summed to produce a General Symptom Score. Participants were then categorized into a high or low Post-exam symptom group and General symptom group. Data were analyzed with a binary logistic regression to determine whether the chronic surveys could predict acute symptom group classification.

RESULTS

Approximately 75% of predictions were accurate for either chronic symptom survey. Headache, soreness, and eye-related questions were more reliable predictors of symptom acute outcome.

CONCLUSIONS

These data suggest that the Conlon and Convergence Insufficiency Symptom Survey (CISS) surveys are good predictors of acute symptoms induced during a binocular examination and validate the use of chronic symptom surveys as screening tools for symptomatic binocular dysfunction. Further investigation is required to determine predictability of accommodative or vergence performance.

Prevalence of asthenopia and its risk factors in Chinese college students

AIM

To determine the prevalence of asthenopia and identify any associated risk factors in the college students in Xi'an, China.

METHODS

From April to September 2012, 1 500 students from five universities in Xi'an were selected according to a multi-stage stratified cluster sampling method. Data on demographic features, lifestyle or dietary habits, health status, living environment conditions, sleep and mental status, and asthenopia symptoms were collected through a self-administered validated questionnaire. Univariate logistic regression and multivariate logistic regression analysis modified by the factor analysis were performed to evaluate risk factors for asthenopia.

RESULTS

Fifty-seven percent of the college students complained of asthenopia. Statistically significant risk factors for asthenopia in the univariate analysis included 13 variables. Multivariate analysis revealed a significant relationship between the use of computer and asthenopia (OR 1.21, 95%CI: 1.09 to 1.35). Good sleep and mental status (OR 0.86, 95%CI: 0.76 to 0.97), good living environment conditions (OR 0.67, 95%CI: 0.60 to 0.76), and high intake of green leafy vegetables (OR 0.89, 95%CI: 0.80 to 0.98) were found to be strong predictors of decreasing the occurrence of asthenopia complaints.

CONCLUSION

Asthenopia symptom appears to be common among college students; and it is strongly associated with computer use, psychosocial state, environment conditions and dietary habits, suggesting that additional studies are warranted to verify these risk factors and establish prevention guidelines, especially for college students.

Diagnostic validity of clinical signs associated with a large exophoria at near

Purpose. To analyze the diagnostic validity of accommodative and binocular tests in a sample of patients with a large near exophoria with moderate to severe symptoms. Methods. Two groups of patients between 19 and 35 years were recruited from a university clinic: 33 subjects with large exophoria at near vision and moderate or high visual discomfort and 33 patients with normal heterophoria and low visual discomfort. Visual discomfort was defined using the Conlon survey. A refractive exam and an exhaustive evaluation of accommodation and vergence were assessed. Diagnostic validity by means of receiver operator characteristic (ROC) curves, sensitivity (S), specificity (Sp), and positive and negative likelihood ratios (LR+, LR-) were assessed. This analysis was also carried out considering multiple tests as serial testing strategy. Results. ROC analysis showed the best diagnostic accuracy for receded near point of convergence (NPC) recovery (area = 0.929) and binocular accommodative facility (BAF) (area = 0.886). Using the cut-offs obtained with ROC analysis, the best diagnostic validity was obtained for the combination of NPC recovery and BAF (S  =  0.77, Sp = 1, LR+ = value tending to infinity, LR- = 0.23) and the combination of NPC break and recovery with BAF (S  =  0.73, Sp = 1, LR+ = tending to infinity, LR- = 0.27). Conclusions. NPC and BAF tests were the tests with the best diagnostic accuracy for subjects with large near exophoria and moderate to severe symptoms.

Measuring near-induced transient myopia in college students with visual discomfort

PURPOSE

Visual discomfort is a common problem, and our previous research indicated that 17% of college students experience moderate to high levels of discomfort when reading or studying. There have been several visual factors associated with visual discomfort, and in this study, we focused on measuring the near-induced transient myopia response in a group of college students with significant visual discomfort.

METHODS

Visual discomfort was evaluated with a survey developed by Conlon et al. (Conlon et al., Visual Cogn 1999;6:637-663). Twelve college students with high visual discomfort (scoring 1 SD higher than the mean value) and 12 college students with low visual discomfort (scoring within 0.5 SD of the mean value) participated in the study. All students had 20/25 or better visual acuity, no strabismus, and no significant uncorrected refractive error. All refractive error and accommodative measurements were made with the WAM-5500 autorefractor. A pretask distance refraction at 6 m was taken for 60 s, and then the students read a story for 10 min at 20 cm. After reading the passage, the posttask distance refraction was measured for 2 min at 6 m. Values for the pre- and posttask measures were averaged in 10-s blocks of time.

RESULTS

A mixed analysis of variance comparing discomfort group by pre- and postnear work distance refraction showed a significant interaction (p = 0.05). Comparing the means of the pre- and posttask distance refraction indicated that the high discomfort group showed no change in refractive error, but the low discomfort group showed a myopic shift of 0.13 diopter.

CONCLUSIONS

A near-induced transient myopia response is not associated with high visual discomfort experienced by college students when reading or doing near work.

Visual discomfort and objective measures of static accommodation

PURPOSE

Accommodation insufficiency and fatigue have been associated with near work visual discomfort symptoms, but clinical measures of accommodation amplitude suggest insufficiency is uncommon and often not weak enough to cause symptoms. However, recent studies show that the clinical push-up test used to measure amplitude overestimates accommodative function. This study uses an open-field autorefractor to measure accommodative stimulus-response functions objectively in college students with and without near work induced discomfort symptoms.

METHODS

Using a Grand-Seiko WAM 5500 autorefractor, 2 min recordings were made each at five viewing distances (0 to 5 D) to measure an accommodative response function. Visual discomfort symptoms were assessed using the Conlon survey.

RESULTS

A strong and positive correlation between accommodative lag and visual discomfort symptoms was found under near work conditions. The prevalence of accommodative insufficiency was much higher than estimated by clinical measures.

CONCLUSIONS

Accommodative insufficiency and fatigue should be defined and described by objective methods using extended viewing times to assess function.

ERGs and psychophysical thresholds in students with reading discomfort

PURPOSE

Symptoms of reading discomfort include unpleasant somatic and perceptual effects, such as eye-strain, headache, and blurred text, despite normal visual acuity. Reading discomfort has been proposed to be the result of increased noise in the visual system. Several studies have suggested that the symptoms can be minimized by having the subject wear colored filters. Thus, there may be abnormal neural processing in the cone pathways. This study measured L- and M-cone isolating (1) ERGs and (2) psychophysical thresholds in normal and reading discomfort subjects to determine if cone processing was abnormal in the reading discomfort population.

METHODS

Twenty-two normal and nineteen reading discomfort college students took part in this study. The normal subjects had Conlon survey scores within 0.5 SD of the mean and the reading discomfort subjects had scores >1.5 SD above the mean. ERGs were determined for a range (5 to 15%) of L- and M-cone contrasts. Slopes were determined for the L- and M-cone ERG amplitudes for each subject. Psychophysical thresholds were determined with a 2AFC technique combined with a 3-up and 1-down staircase procedure that terminated after 18 reversals occurred. The threshold was calculated as the average of the last 8 reversals.

RESULTS

The average ERG slopes were not significantly different between the normal and reading discomfort groups (L-Cone, p = 0.086; M-Cone, p = 0.47). The L/M cone ratios for the slopes were not significantly different (p = 0.55). The log of the color contrast thresholds were not significantly different between the normal and reading discomfort groups (L-Cone, p = 0.97; M-Cone, p = 0.92).

CONCLUSIONS

L- and M- cone ERG contrast gains and psychophysical estimates of color contrast thresholds were not significantly different. These results do not support the noisy visual system hypothesis of reading discomfort.