Incomplete Blinks Research Articles

Dry eye disease as an occupational risk factor in operating room nurses

ABSTRACT Clinical relevance Knowing occupational risks in a multifactorial disease such as dry eye disease is important for disease diagnosis and treatment. Background Dry eye disease (DED) is a multifactorial disease of the ocular surface characterised by tear film instability, adversely affecting visual function and quality of life. The operating room environment has many risk factors for DED such as air conditioning, constant humidity, constant room temperature, intense lighting, surgical smoke, anaesthetic gases and irritating chemicals, and prolonged mask use. This study investigates the ocular surface findings and blink patterns of operating room nurses at risk of DED. Methods A total of 68 nurses (operating room, n = 34; outpatient clinic, n = 34) were included in this study. The diagnosis of DED was assessed using a questionnaire, best-corrected visual acuity, tear break-up time, corneal fluorescein staining, meibomian gland assessment, Schirmer I test. All the tests were conducted in the same area. Results According to the ocular surface disease index, the rate of dry eye symptoms was significantly higher among operating room nurses than among outpatient nurses (70.5% vs 41.1%). Severe dry eye symptoms were more common in the operating room group. The meibomian gland score was higher in the operating room group (29.4% vs 5.9%). The numbers of blinks (30.91 ± 12.81 vs 21.05 ± 7.77) and incomplete blinks (8.76 ± 4.68 vs 5.76 ± 3.20) at rest were higher in operating room nurses. Conclusion The occupational risk for DED was high among operating room staff. National and international standards for the prevention and management of DED in personnel involved in health care services are needed.

Practical Application of Intelligent Vision Measurement System Based on Deep Learning

To comprehensively assess the true visual function of clinical dry eye patients and the comprehensive impact of blinking characteristics on functional vision of the human eye, an intelligent vision measurement system has been designed and developed to detect and analyze blinks from the side. The system employs deep learning keypoint recognition technology to analyze eyelid features from a lateral perspective. It presents the data of identified key points for the upper and lower eyelids in a line chart format and annotates the trough of each blink. By setting benchmark values, the system automatically calculates the proportion of complete and incomplete blinks in the tested individuals. The results indicate that the system is stable in performance and accurate in measurement, successfully achieving the anticipated design objectives. It thereby provides reliable technical support for future clinical applications.

Assessing blink dynamics with non-noticeable method

PurposeThe purpose of the study was to demonstrate the feasibility of blink dynamics with a contactless, non-noticeable method without any visible light being reflected to the participant’s eye by the device, and to investigate the blink dynamics parameters in 39 participants whose blink dynamics were examined with this method. It was also aimed to explain the potential of corneal topography devices for non-noticeable blink dynamics and elucidate some tips to device manufacturers to make them practical. MethodsA one-minute real-time video image in the meibography module of the scheimpflug camera-based corneal topography device was recorded in the slow motion mode of the mobile phone. Detailed analysis of blink dynamics was made by advancing the video images manually at 10 ms intervals. Lid Closing Time (LCT), Lid Opening Time (LOT), third Interblink Interval times (IBI(3)), fifth Interblink Interval times (IBI(5)), Number of Blinks Per Minute (NoB), Number of Complete Blinks Per Minute (NoCB), Number of Incomplete Blinks Per Minute (NoICB) were investigated. ResultsThe average NoB, NoCB, and NoICB (blinks/minute) with ± standard deviation (SD) values were found to be 22.9 ± 14.4; 14.5 ± 12.4 and 8.4 ± 8, respectively. The average IBI(3) time(seconds) with ± SD was measured as 3.4 ± 4.5. The average IBI(5) time (seconds) with ± SD was 3.9 ± 3.7 The average LCT time (milliseconds) with ± SD was found to be 91.9 ± 36.9 in the 4 different blinks analyzed. The average LOT time (milliseconds) with ± SD was found to be 582.6 ± 196.5 in the 3 different blinks analyzed. ConclusionsBlink dynamics can be examined in detail with corneal topography devices in a non-contact, no visible light, and most importantly, non-noticeable manner. Existing video imaging modules of corneal topography devices have the potential to investigate blink dynamics. It is anticipated that the clinical use of blink dynamics, which can be performed practically, will increase, particularly in the monitoring of ocular surface and neurological diseases.

Eye-LRCN: A Long-Term Recurrent Convolutional Network for Eye Blink Completeness Detection.

Computer vision syndrome causes vision problems and discomfort mainly due to dry eye. Several studies show that dry eye in computer users is caused by a reduction in the blink rate and an increase in the prevalence of incomplete blinks. In this context, this article introduces Eye-LRCN, a new eye blink detection method that also evaluates the completeness of the blink. The method is based on a long-term recurrent convolutional network (LRCN), which combines a convolutional neural network (CNN) for feature extraction with a bidirectional recurrent neural network that performs sequence learning and classifies the blinks. A Siamese architecture is used during CNN training to overcome the high-class imbalance present in blink detection and the limited amount of data available to train blink detection models. The method was evaluated on three different tasks: blink detection, blink completeness detection, and eye state detection. We report superior performance to the state-of-the-art methods in blink detection and blink completeness detection, and remarkable results in eye state detection.

Loss of Blink Regularity and Its Impact on Ocular Surface Exposure.

(1) Background: Changes in blink parameters have been found to influence ocular surface exposure, eliciting symptoms of dry eye and ocular signs. The aim of the study was to highlight the relevance of including blink regularity as a new parameter to fully characterize blinking; (2) Methods: A novel characterization of blink parameters is described, including spontaneous eyeblink rate (SEBR), percentage of incomplete blinks, and blink regularity. A pilot study was designed in which tear film break-up time (TFBUT), blink parameters, and the time percentage of ocular surface exposure were determined in eight subjects (52.0 ± 16.6 years, 4 females) in three experimental conditions (baseline, reading a hard-copy text, and reading from an electronic display). Blink parameters were monitored through asynchronous image analysis of one minute video segments; (3) Results: All blink parameters were influenced by experimental conditions. A trend was observed in which both reading tasks resulted in an increase in ocular surface exposure, mainly related to a combination of reduced SEBR, increased percentage of incomplete blinks, and loss of blink regularity; (4) Conclusions: A complete characterization of blink parameters is relevant to better understand ocular dryness related to surface exposure and to advice patients towards a reeducation of their blinking habits.

The short-term influences of paediatric smartphone use on the eye

The aim of this study is to comprehensively evaluate the effect of smartphone use on the eye. Twenty-two children, aged 8-16 years, participated in this study. A self-administered questionnaire about smartphone usage time, outdoor activities, and sleep time to obtain dry eye was applied to the child and parents. An ocular surface disease index (OSDI), tear break-up time (TBUT), blink time, autorefractometer, optical biometry, accommodation, contrast sensitivity, and optical coherence tomography tests were applied before a 5-min video watching, and during the video session we counted the complete -incomplete blinks. After video watching, we did the tests. After the tests, we again applied a 5-min video watching and after the video we tested all the parameters again, and finally, following a 5-min resting period, we tested the parameters again. We found no difference between the groups in terms of OSDI scores. Children with punctate epithelial erosions and time spent on the phone have a statistical relation. TBUT also differs statistically before and after test periods ( p = .014), since complete blinks did not differ but incomplete blinks differed before and after video watching. The nearpoint of convergence also differs after video watching ( p = .008) and anterior chamber depth (ACD) decreases even after the short-time video watching period. On the contrary, we did not find any effect of short-time smartphone watching on auto-keratometer values and retinal-choroidal thickness. This is the first comprehensive study on the short-term effects of smartphone on the paediatric age group. Even 10 min of smartphone can have an effect on TBUT, incomplete blinks, nearpoint of convergence break-recovery, and ACD. During this coronavirus disease 2019 pandemic, we must be mindful of the time our children spend on the phone and keep in mind that even 10 min can have ocular effects.

Automated segmentation of palpebral fissures from eye videography using a texture fusion neural network

Automated segmentation of palpebral fissures depicted on images of eye videography plays a crucial role in identifying blinks (especially incomplete blinks) and detecting some eye disorders (e.g., dry or tired eyes). To this end, we propose a texture fusion segmentation network (called TF-Net) on the basis of the popular U-Net for automatically segmenting palpebral fissures from eye videography. The proposed network is constructed by defining two novel subtraction convolutional blocks and introducing them into the U-Net. These subtraction blocks are able to suppress motion artifacts and complex background in some degrees and enhance the sensitivity of the proposed network to objects of interest, as compared to the U-Net. Extensive experiments on our collected blink images from eye videography and three public datasets demonstrated that the proposed network obtained, on average, the Dice score (DS), Jaccard similarity (JS), and Hausdorff distance (HD) of 0.9445, 0.9099, and 5.3657, respectively, on the blink image dataset, and 0.8364, 0.7434, and 4.5745 for 14 objects of interest on three public datasets, which surpassed the U-Net and its multiple variants.

Effectiveness of Blinking Therapy in Dry Eye Disease: An Evidence-Based Case Report

Background: Dry eye disease (DED) is a group of tear film disturbances that are caused by a decrease in tear production or tear film instability. One of the causes of DED is reduced tear secretion, which often happens in visual display terminal (VDT) workers. Blinking therapy is one of the therapies that can be given to DED workers to increase blink rate and reduce the number of incomplete blinks. Methods: Literature searching was done on database such as Pubmed, Cochrane Library, and Google Scholar. The keywords used in the literature search were dry eye disease, blinking therapy, and ocular surface disease index. Three articles were chosen and critically appraised. Results: Blinking therapy can be done using conventional methods, using animation software on a computer, or by using specifically designed wink glass. Blinking therapy showed statistically significant changes in OSDI scores, with therapy duration ranging from 20 minutes to 4 weeks. Conclusion: Blinking therapy can be done as a treatment for DED workers to improve dry eye symptoms as measured in OSDI.

Structural and functional alterations in corneal nerves after single-step transPRK.

To evaluate the relationship between structural and functional changes of corneal subbasal nerves after single-step transepithelial photorefractive keratectomy (TransPRK). Tianjin Medical University Eye Hospital. Prospective observational study. 51 eligible candidates who underwent TransPRK for moderate myopia were included. The regeneration of corneal subbasal nerves were evaluated by in vivo confocal microscopy (IVCM) prior to surgery and at 1 week and 1 month, 3 months, 6 months, and 12 months postoperatively. The corneal sensitivity was measured by Cochet-Bonnet esthesiometer. The number of complete and incomplete blinks were recorded by LipiView interferometer. A correlation analysis was performed between these variables. 51 eyes of 51 patients were enrolled in this study. IVCM revealed that the density and length of corneal nerve decreased immediately and did not return to preoperative levels by 12 months post-TransPRK ( P < .01). The mean corneal sensitivity was slightly lower compared with preoperative levels at 1 week postoperatively ( P = .001) and then increased to baseline preoperative level within 1 month postoperatively. Mean total blink frequency and the partial blink rates had no statistically significant change postoperatively ( P = .087). There was no direct correlation between postoperative recovery of corneal sensitivity, changes in blink frequency, and regeneration of subbasal corneal nerve. The significant and prolonged decrease in corneal subbasal nerve morphology was accompanied by only a slight and transient reduction in corneal sensitivity to mechanical stimuli within 1 month after TransPRK. The results demonstrated that the structural changes of subbasal nerves were not parallel to their functional changes after TransPRK.

Video-Based Eye Blink Identification and Classification.

Blink detection and classification can provide a very useful clinical indicator, because of its relation with many neurological and ophthalmological conditions. In this work, we propose a system that automatically detects and classifies blinks as "complete" or "incomplete" in high resolution image sequences zoomed into the participants' face, acquired during clinical examination using near-Infrared illumination. This method utilizes state-of-the-art (DeepLabv3+) deep learning encoder-decoder neural architecture -DLED to segment iris and eyelid in both eyes in the acquired images. The sequence of the segmented frames is post-processed to calculate the distance between the eyelids of each eye (palpebral fissure height) and the corresponding iris diameter. These quantities are temporally filtered and their fraction is subject to adaptive thresholding to identify blinks and determine their type, independently for each eye. The proposed system was tested on 15 participants, each with one video of 4 to 10 minutes. Several metrics of blink detection and classification accuracy were calculated against the ground truth, which was generated by three (3) independent experts, whose conflicts were resolved by a senior expert. Results show that the proposed system achieved F1-score 95.3% and 80.9% for the classification of complete and incomplete blinks respectively, collectively for all 15 participants, outperforming all 3 experts. The proposed system was proven robust in handling unexpected participant movements and actions, as well as glare and reflections from the spectacles, or face obstruction by facemasks.

Blinking and upper eyelid morphology

PurposeTo explore blinking patterns and sagittal eyelid misalignment in the East Asian eye. MethodsForty-four participants (22 females; age 26 ± 5 years; 52% of East Asian ethnicity) were enrolled in this pilot study and subdivided, based on upper eyelid crease presence and extent, into single (n = 10), partial (n = 11) or double (n = 23) eyelid crease groups. Blinking was filmed surreptitiously with high-speed video simultaneously from an inferior temporal and frontal view. Spontaneous blink rate and type (incomplete, almost complete, or complete) were assessed over a 30 s period. Sagittal misalignment of the lids on closure was graded during complete spontaneous blinks, voluntary lid closure and voluntary maximal lid contraction (squeezing). A 0.15 µL drop of lissamine green was placed on the central lower lid margin and the number and type of blinks required to eliminate the drop informed complete palpebral apposition during blinking. ResultsMean ± SD blink rates averaged 16.9 ± 10.5 blinks/minute. The proportion of incomplete blinks was 83 ± 22% in single, 58 ± 35% in partial and 59 ± 30% in double eyelid crease groups. The sagittal misalignment of the lid margins during blinking was limited to approximately one-third of the lid margin width; this was similar for all lid morphologies and blink types. The lissamine green drop was eliminated only by voluntary maximal lid contraction, and was similar in all groups (p = 0.97). ConclusionsIncomplete blinking and sagittal lid misalignment of the central eyelid margin predominate in habitual blinking, irrespective of lid morphology.

Review on the possible pathophysiological mechanisms underlying visual display terminal-associated dry eye disease.

Visual display terminal (VDT) use is a key risk factor for dry eye disease (DED). Visual display terminal (VDT) use reduces the blink rate and increases the number of incomplete blinks. However, the exact mechanisms causing DED development from VDT use have yet to be clearly described. The purpose of the study was to conduct a review on pathophysiological mechanisms promoting VDT-associated DED. A PubMed search of the literature investigating the relationship between dry eye and VDT was performed, and relevance to pathophysiology of DED was evaluated. Fifty-five articles met the inclusion criteria. Several pathophysiological mechanisms were examined, and multiple hypotheses were extracted from the articles. Visual display terminal (VDT) use causes DED mainly through impaired blinking patterns. Changes in parasympathetic signalling and increased exposure to blue light, which could disrupt ocular homeostasis, were proposed in some studies but lack sufficient scientific support. Together, these changes may lead to a reduced function of the tear film, lacrimal gland, goblet cells and meibomian glands, all contributing to DED development. Visual display terminal (VDT) use appears to induce DED through both direct and indirect routes. Decreased blink rates and increased incomplete blinks increase the exposed ocular evaporative area and inhibit lipid distribution from meibomian glands. Although not adequately investigated, changes in parasympathetic signalling may impair lacrimal gland and goblet cell function, promoting tear film instability. More studies are needed to better target and improve the treatment and prevention of VDT-associated DED.

Ocular surface predisposing factors for digital display-induced dry eye

ABSTRACT Clinical relevance The use of digital displays is recognised as a consistent risk factor for dry eye disease. Background To identify ocular parameters contributing to the impact of computer use on dry eye. Methods The ocular surface of 82 undergraduate students with a mean age of 22.8 ± 2.1 years was assessed at baseline and after reading on a computer for 30 minutes. Measurements included the ocular surface disease index (OSDI) questionnaire, 5-item dry eye questionnaire (DEQ-5), tear meniscus height, non-invasive keratograph break-up time (NIKBUT), conjunctival bulbar redness, meibomian gland dropout percentage, spontaneous blink rate and percentage of incomplete blinks. Multiple linear regressions and generalised linear mixed models were conducted to explore the associations between baseline parameters and pre-task – post-task differences and to predict the impact of computer use, respectively. Results Greater dry eye symptoms (p < 0.0005), higher tear meniscus height and conjunctival bulbar redness (p < 0.0005 and p = 0.012, respectively) and shorter NIKBUT (p = 0.03) were obtained after reading on the computer for 30 minutes. The baseline score obtained with the OSDI and DEQ-5 was positively associated with the increase in symptoms with computer use (p < 0.0005), while the change in conjunctival redness and pre-task NIKBUT were associated with the change in NIKBUT (p ≤ 0.005). No ocular surface parameter revealed an association with tear meniscus height changes. Having a positive OSDI score at baseline increased the odds of painful and sore eyes (p = 0.012), while a higher pre-task NIKBUT increased the odds of a reduction in tear stability (p = 0.038). Conclusions Participants with greater dry eye symptoms were more likely to experience a greater increase in symptomatology with computer operation, while the participants with longer NIKBUT and greater conjunctival redness were more likely to suffer a greater reduction in tear stability.

Video display terminal use and dry eye: preventive measures and future perspectives.

Dry eye disease (DED) is a common cause of ocular pain and discomfort. Dry eye disease (DED) stems from a loss-of-tear film homeostasis and is frequently seen in video display terminal (VDT) users. Video display terminal (VDT) use reduces blink rates and increases incomplete blinks, leading to tear film instability and ocular inflammation, promoting DED. To assess and evaluate the methods for preventing VDT-associated DED and ocular discomfort. Studies were found using PubMed and Embase with the search terms: (digital visual terminal* OR computer use OR screen use OR smartphone OR display OR visual display terminal* OR computer vision syndrome OR tablet OR phone OR screen time) AND (dry eye OR DED). Thirty-one relevant articles were found. Ten described single-visit studies, whereas 21 had a prolonged follow-up. Most preventive measures of VDT-associated DED aimed to increase blink rate or directly prevent tear film instability, ocular inflammation, mucin loss or ocular surface damage. Using an adjustable chair and ergonomic training, blink animations and omega-3 supplementation improved signs and symptoms of VDT-associated DED. Taking frequent breaks was associated with fewer symptoms, but no study assessed the commonly suggested 20-20-20 rule. Preventive measures, such as blink animation programmes, oral intake of omega-3 fatty acids and improved ergonomics act on different parts of the vicious cycle of dry eye and could supplement each other. A comparison of the efficacy of the different interventions as well as more evidence of the effect of increased humidity, VDT filters and ergonomic practices, are required.

Effects of aerobic exercise on tear secretion and tear film stability in dry eye patients

BackgroundTo study the effects of aerobic exercise (AE) on tear secretion and tear film stability in dry eye patients.MethodsThis study consisted of two parts, each part included 3 groups, namely dry eye without AE group, dry eye with AE group and pre-clinical dry eye with AE group. In part 1, we studied the variations of Schirmer I test and six tear compositions before and after AE (34 eyes in each group). In part 2, we studied the variations of tear meniscus height, first and average non-invasive tear breakup time (F-NITBUT and A-NITBUT), lipid layer thickness, number of incomplete and complete blinks, partial blink rate (PBR) and visual acuity before and after AE (30 eyes in each group).ResultsIn dry eye with AE group, Schirmer I test at 0 min after AE increased significantly compared to baseline (P < 0.001), the oxidative stress marker 8-hydroxy-2′-deoxyguanosine after AE decreased significantly compared to baseline (P = 0.035, P = 0.045), F-NITBUT and A-NITBUT after AE prolonged significantly compared to baseline (P < 0.001, P = 0.007, P = 0.036; P < 0.001, P = 0.001, P = 0.044), number of incomplete blinks and PBR at 10 min after AE decreased significantly compared to baseline (P < 0.001; P < 0.001) while number of complete blinks increased significantly (P < 0.001). Besides, significant differences were also found between dry eye with AE group and dry eye without AE group at all above corresponding time point (P < 0.05).ConclusionAE promotes tear secretion and improves tear film stability in dry eye patients. AE may be a potential treatment for dry eye.Trial registrationChinese Clinical Trial Registry, ChiCTR2000038673. Registered 27 September 2020,

Blinking kinematics characterization during digital displays use

PurposeThis study aimed to assess the differences in blinking kinematics while reading on different digital displays and a control condition.MethodsThirty-two young healthy individuals were included in this prospective clinical study. The blinks of subjects were recorded for 150 s while reading on a laptop computer, tablet, e-reader, and smartphone and a control condition. Blinks were recorded using an eye-tracking device and were analyzed by means of image analysis to obtain a non-invasive detailed description of the blink movement.ResultsBlink rate decreased when reading on all displays compared to the control (p < 0.0005), although no differences were obtained amongst displays (p > 0.05). The percentage of incomplete blinks was higher with the computer compared to the control (p = 0.043), and lower with the smartphone compared to the rest of the conditions (p ≤ 0.015). Blink amplitude was smaller when reading from handheld devices compared to the control (p < 0.0005) and the computer (p ≤ 0.048). Closing and opening blink durations remained unvaried amongst conditions (p > 0.05), while opening and closing speeds were greater for the control and the computer compared to the handheld displays (p < 0.0005). Finally, contact and total blink durations were shorter during computer reading compared to the control (p = 0.004 and p = 0.017, respectively).ConclusionBlinking kinematics vary considerably amongst displays and with respect to baseline, with these differences being probably attributed to differences in the way the displays are set up and the cognitive demand of the task.

Assessment of spontaneous eye blink rate in online livestream videogame players

Introduction: The normal blink rate for humans is between 12 and 15 blinks per minute (bpm). Screen use has been associated with decreased blink rate and increased percentage of incomplete blinks, however, little is known about the effects of videogaming on blink rate. The purpose of this study was to assess the blink rate of online livestream video game players. Methods: A total of 30 livestream video gamers across YouTube, Twitch, and Facebook Gaming were selected for this study. Video gamers were characterized by gender and whether or not they were wearing glasses. Blink rate was observed for 5 minutes and defined as a complete closure of the ocular surface. Descriptive statistics and linear regression were used to determine significance (p&lt;0.05) between variables. All analyses were conducted using RStudio (version 1.3.1056; RStudio, Inc). Results: The study population comprised of 30 video game players (50% men). The mean (standard deviation [SD]) blink rate of the total study population was 14.79 (8.79) bpm. Compared to male gamers, female gamers had a higher mean blink rate, however this was not statistically significant (17.07 vs. 12.51, p=0.16). A total of 3 (10%) video game players wore glasses. The difference in blink rate between video game players wearing and not wearing glasses was not statistically significant (14.07 vs 14.87, p=0.88). Conclusions: The average blink rate of select livestream video game players was observed to be within the range of normal spontaneous blink rates. The observed blink rate between male and female gamers did not differ. More research in controlled environments would help to elucidate the blink rate and patterns of video game players

Characteristics of tear film lipid layer in young dry eye patients

To investigate the characteristics of subjective symptoms and objective parameters among young patients with dry eye disease (DED) and compare them with those of older patients. We retrospectively enrolled 675 patients with DED who were divided into three age groups (20-41 years [younger], 41-60 years [middle], and >60 years [older]) (n=143, 304, and 228, respectively). Subjective symptoms were evaluated using Standardized Patient Evaluation of Eye Dryness (SPEED) and Ocular Surface Disease Index (OSDI) questionnaires. Aqueous tear secretion was evaluated with the Schirmer test II. The number of expressible meibomian glands was evaluated with a slit-lamp-aided standardized evaluator. Lipid layer thickness (LLT), blink/incomplete blink rates and meibography were measured with the LipiView® II interferometer. The extent of the meibomian gland dropout was graded using a meiboscale. The younger age group had higher subjective symptom severity, as reflected by higher SPEED (p<0.001) and OSDI scores (p=0.051). The SPEED scores negatively correlated with LLT in all patients (r=-0.136, p<0.001). Younger patients also had thinner average LLT (p<0.001), lower meiboscale (p<0.001) and a higher number of expressible meibomian glands (p<0.001). Additionally, they had significantly more total blinks (p<0.001), incomplete blinks (p<0.001), and incomplete blink rate (p=0.006). Manifestations of DED vary with age. In our cohort, younger age patients had more symptoms and blinks, which may have resulted from thinner LLT as the structure and function of the meibomian glands were affected less than in middle and older age patients.

Double Eyelid Tape Wear Affects Anterior Ocular Health among Young Adult Women with Single Eyelids

Many East Asians apply double eyelid tape to create the double eyelid effect temporarily as a means of increasing their beauty. This study evaluated the effects of four-week wear of double eyelid tape on anterior ocular health in young adult women with single eyelids. Twenty-nine participants who met the inclusion criteria were recruited. The participants’ anterior ocular health was examined including blinking characteristics (blink pattern and blink rate), ocular surface health (presence of corneal abrasion, corneal staining, conjunctival staining, corneal curvatures, meibomian gland dysfunction), tear break up time, intraocular pressure, and subjective comfort level. Participants were required to apply the double eyelid tape for at least eight hours a day and five days a week for four weeks. The parameters were re-measured at the end of each week. There was a significant increase in conjunctival staining, corneal staining, and meibomian gland dysfunction, with a significant reduction in tear break-up time and intraocular pressure. By week 3, all participants had incomplete blinks. There was no significant change in symptoms and subjective comfort level reported. Therefore, patients and eye care practitioners should be aware of the potential implications of double eyelid tape wear on ocular health, with no significant change in subjective comfort.

Non-invasive high-speed blinking kinematics characterization.

The objective of this study was to analyze the differences in blinking kinematics of spontaneous and voluntary blinks using for the first time a self-developed, non-invasive, and image processing-based method. The blinks of 30 subjects were recorded for 1 min with the support of an eye-tracking device based on a high-speed infrared video camera, working at 250 frames per second, under two different experimental conditions. For the first condition, subjects were ordered to look in the straightforward position at a fixation target placed 1 m in front of them, with no further instructions. For the second, subjects were additionally asked to blink only following a sound signal every 6 s. Mean complete blinks increased by a factor of 1.7 from the spontaneous to the voluntary condition while mean incomplete blinks reduced significantly by a factor of 0.4. In both conditions, closing mean and peak velocities were always significantly greater and durations significantly lower than opening ones. When comparing the values for each condition, velocities and amplitudes for the voluntary condition were always greater than the corresponding values for spontaneous. Voluntary blinks revealed significant kinematic differences compared to spontaneous, thus supporting a different supranuclear pathway organization. This study presents a new method, based on image analysis, for the non-invasive kinematic characterization of blinking.