Jesús Vera

University of Granada | UGR · Department of Optics

Purpose: The ±2.00 D accommodative facility test presents several limitations, including the lack of objective information and inherent characteristics such as vergence/accommodative conflict, change in apparent size of the image, subjective criteria for judging blur and motor reaction time. By using free-space viewing conditions and an open-field...

Objectives: A variety of factors are known to mediate on the intraocular pressure (IOP) response to resistance training. However, the influence of the body position adopted during resistance training on IOP remain unknow. The objective of this study was to determine the IOP response to the bench press exercise at three levels of intensity when perf...

A military-specific reaction time (RT) test was developed to explore its reliability and sensitivity to discriminate between military personnel and sport science students. Fifteen male professional Spanish soldiers and 16 male sport science students completed two RT test modalities: military-specific and nonspecific RT tests. For each RT test modal...

Several questionable research practices have been detected by the scientific community, with some of them being associated with the actual format of scientific publication. The eld of ophthalmology, optometry and vision sciences is not exempt of this problematic. This article has been written to describe the Registered Reports format of scientific...

Background The ability to track multiple objects plays a key role in team ball sports actions. However, there is a lack of research focused on identifying multiple object tracking (MOT) performance under rapid, dynamic and ecologically valid conditions. Therefore, we aimed to assess the effects of manipulating postural stability on MOT performance....

Background The aim of the present study was to explore whether military-specific reaction time (RT) test performance is affected by individuals’ physical and visual skills. Method In a single testing session, the military-specific Simple and Go, No-Go RT, aerobic power (20-m Multistage Shuttle Run test), maximal upper- and lower-body mechanical ca...

Ocular physiology is sensitive to cognitively demanding tasks. However, it is unknown whether the intraocular pressure is also affected by the cognitive demands of military operations. The main objective was to determine the impact of a virtual reality shooting simulation with two levels of complexity on intraocular pressure levels in military pers...

Objective: To determine the effect of blood flow restriction (BFR) applied to the legs at different pressures (40% and 60%) on intraocular pressure (IOP) during the execution of ten repetitions maximum (10RM) in the half-squat exercise. Methods: Quasi-experimental, prospective study with 17 healthy physically active subjects (9 males and 8 females;...

Introduction: There is scientific evidence that individuals´ beliefs/expectations play a role on the behavioral and physiological response to a given treatment. This study was aimed at assessing whether the dynamics of the accommodative response and stereoacuity are sensitive to experimentally-induced placebo and nocebo effects. Methods: Nineteen...

The main objective of this study was to determine the influence of physical fitness level and sex on intraocular pressure (IOP) during the low-intensity aerobic exercise. Forty-four participants (twenty-two men) cycled 30 minutes at low intensity (10% of the maximal power). Maximal power was determined by asking participants to perform maximal spri...

We assessed the association between measures of dynamic visual acuity and a multiple object tracking task in physically active young adults. Ninety-four young adults (55 males and 39 females) performed the dynamic visual acuity and multiple object tracking tasks. Dynamic visual acuity was measured for horizontal and random walk motion paths at four...

Purpose: This study aimed to assess the impact of wearing swimming goggles (SG) on corneal biomechanics. Methods: Corneal deformation response, central corneal thickness (CCT), intraocular pressure (IOP) and biomechanically-corrected intraocular pressure (bIOP) were measured with the Corvis system (Oculus Optikgeräte GmbH, Wetzlar, Germany) in th...

Clinical relevance: The use of face masks has demonstrated to be an effective strategy to prevent transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Wearing face masks, mainly FFP2 (Filtering Face Piece 2) masks, during exercise practice has demonstrated to affect several physiological measures, but its impact on intraocu...

Objectives: The execution of isometric resistance training has demonstrated to cause changes in the ocular physiology. The morphology of the cornea and anterior chamber is of paramount importance in the prevention and management of several ocular diseases, and thus, understating the impact of performing isometric exercise on the eye physiology may...

Introduction: Dual-focus soft contact lenses for myopia management have demonstrated to be an effective strategy to reduce myopia progression. However, this optical design has shown to alter visual quality and accommodative function. The aim of this study was to examine the accommodative and behavioral performance during the execution of a psychomo...

Purpose: We aimed to assess the impact of drinking water (500ml, 1000ml) on the corneal biomechanics, as well as to determine the level of association between changes in intraocular pressure and variations in the different biomechanical properties of the cornea. Study design: Experimental study. Methods: Thirty-nine healthy young adults ingested e...

Clinical relevance: Dual-focus soft contact lenses are effective in slowing myopia progression, however, their influence on nearwork-induced transient myopia (NITM) remains unknown. When performing a 5-min near task at 20 cm, we observed that dual-focus soft contact lens wear induced greater lags of accommodation and a lower initial NITM than singl...

Clinical relevance: There is some controversy about the utility of prescribing blue-blocking (B-B) filters to mitigate digital eye strain. We found that using a commercially available blue-blocking filters was ineffective in reducing orbicularis oculi muscle activity and visual symptomatology during a 30-min reading task from a computer screen. Ba...

Background: Acute caffeine ingestion has been associated with improvements in cognitive performance and visual functioning. The main objective of this study was to determine the effects of caffeine intake on dynamic visual acuity (DVA). Methods: Twenty-one low caffeine consumers (22.5 ± 1.6 years) took part in this placebo-controlled, double-blind...

Clinical relevance: Steady-state accommodation is frequently evaluated with open-field autorefractors, however there is no consensus regarding the optimal test duration. Our results permit to standardize the procedure followed for the assessment of the steady-state accommodative response in clinical and laboratory settings and may be of great relev...

Objective: To assess the impact of using dual-focus soft contact lenses for myopia control on the dynamics of the accommodative response and facility. Methods: 24 young adult myopes were fitted with dual-focus soft contact lenses for myopia control (MiSight®) and single-vision soft contact lenses (Proclear®). The WAM-5500 open-field autorefractor...

Purpose: The use of face mask is globally recommended as a preventive measure against COVID-19. However, the intraocular pressure (IOP) changes caused by face masks remains unknown. The objective of this study was to assess the impact of wearing surgical and FFP2/N95 face masks during a 400-m walking protocol on IOP in primary open-angle glaucoma (...

Purpose: Recent technological advances allowed the objective recording the accommodative response while shifting between two different levels of accommodation. This study is aimed at examining the concurrent validity of a new objective method for the qualitative and quantitative assessment of binocular accommodative facility, which is named 2Q-AF t...

Clinical relevance: Caffeine intake has been demonstrated to influence several physiological measures, including some related to eye physiology. The ability to focus at different distances is of paramount importance in real-world situations, and thus, the possible impact of caffeine intake on accommodative facility may have important applications....

The present study was aimed at assessing the impact of manipulating the attentional load using a multiple object tracking (MOT) task on the dynamics of the accommodative response in children with attention deficit and hyperactivity disorder (ADHD). The pupil size was recorded to assess the effectiveness of the experimental manipulation, and the rol...

Purpose: To assess the influence of wearing an elevation training mask (ETM) on IOP during low-intensity endurance training. Methods: 16 physically active young adults (age = 23.9 ± 2.9 years) cycled during 30 minutes at 10% of maximal power production with and without an ETM in two different days and randomized order. A rebound tonometer was used...

Purpose: To assess the short-term effects of caffeine intake on the biomechanical properties of the cornea, as well as its possible association with the intraocular pressure (IOP), as measured by corneal visualization Scheimpflug technology (CorVis ST) in healthy subjects. Methods: Twenty-two low caffeine consumers ingested either a caffeine (4mg/...

Purpose: The use of swimming goggles (SG) has demonstrated to alter different ocular parameters, however, the impact of wearing SG on the tear film stability remain unknown. The main objective of this study was to determine the short-term effects of wearing SG on tear film surface quality break-up time (TFSQ-BUT). Methods: Twenty-eight young health...

Introduction The prescription of blue‐blocking (B‐B) filters for the management of visual symptoms and signs associated with the use of electronic devices is routinely performed by eye care specialists. However, the utility of B‐B filters is a matter of debate and discussion by the scientific community due to the lack of evidence supporting their u...

Appropriate visual function is paramount to ensuring adequate driving performance and road safety. Here, we examined the influence of artificially-impaired binocular vision on driving performance using a car simulator. Twenty-four young drivers (aged 22.42 ± 3.19 years) drove under three different visual conditions (natural driving, monocular blur,...

Purpose: To determine the intraocular pressure (IOP) changes caused by the execution of lower-body and upper-body resistance-training exercises leading to muscular failure depending on the exercise phase (concentric vs. eccentric). We also assessed the influence of the exercise type (back squat vs. biceps curl) and level of effort on the IOP respon...

Individuals with attention deficit hyperactivity disorder (ADHD) frequently exhibit different types of visual deficits. This study investigates the dynamics of ocular accommodation and pupil size in a population of children with ADHD (6–14 years old) and assesses the association between these ocular variables with behavioural performance during a c...

We assessed the mediating role of the breathing pattern adopted during isometric exercise on the intraocular pressure (IOP) response in the back squat and biceps curl exercises. Twenty physically active young adults performed sets of 1-minute isometric effort against a load corresponding to 80% of the maximum load while adopting three different bre...

Background: There are claims that ocular accommodation differs in children with attention deficit hyperactivity disorder (ADHD) compared to typically-developing children. We examined whether the accommodation response in ADHD children is influenced by changing the stimulus to accommodation in an attempt modify the level of attentional engagement, o...

Purpose: To assess the mediating role of strength levels, hand dominance and participants´ sex on the intraocular pressure (IOP) behaviour during the execution of a maximal isometric handgrip test. Methods: One hundred and seventy-six sport science students (102 men and 74 women) performed a maximal isometric handgrip test with the dominant and no...

We examined the IOP responsiveness to oral examination stress, as well as the mediating role of the perceived levels of public speaking anxiety on IOP changes. Thirty-two university students (intervention group) publicly defended their degree final project, and IOP and perceived levels of stress were measured before and after the oral presentation,...

Significance: The performance of resistance exercise has evidenced to induce abrupt intraocular pressure (IOP) changes, which has been linked to the onset and progression of glaucoma. We found that four different isometric resistance exercises lead to an instantaneous and progressive IOP elevation, with these changes being independent of the type...

Purpose: There is evidence that attention can modulate ocular dynamics, but its effects on accommodative dynamics have yet to be fully determined. We investigated the effects of manipulating the capacity to focus on task-relevant stimuli, using two levels of dual-tasking (arithmetic task) and auditory feedback, on the accommodative dynamics at thre...

Précis: Greater intraocular pressure values are observed when reading in supine in comparison to sitting position, and thus, it should be considered by eye care specialists for the management of glaucoma patients or those at risk. Purpose: Intraocular pressure (IOP) is sensitive to near-work and body position, however, the influence of the body p...

Importance: Intraocular pressure (IOP) is sensitive to caffeine intake and physical exercise. However, the combined effect of caffeine intake and physical exercise on IOP levels remains unknown. Background: We aimed to assess the effects of caffeine consumption before exercise on the IOP behavior during low-intensity endurance exercise. Design: A...

Background: Acute caffeine consumption causes a transient increase in IOP, however, the mechanisms underlying this phenomenon remain unknown. This study aims to determine the structural changes in cornea and anterior chamber associated with caffeine ingestion. Methods: Seventeen healthy low caffeine consumers ingested a capsule of caffeine (~ 4 mg...

Objectives: To evaluate the acute effect of caffeine consumption on the accuracy and variability of accommodation, as well as its impact on pupil size and perceived levels of activation. Methods: 22 university students (21.68 ± 3.67 years old) ingested a capsule of caffeine (4 mg/kg) or placebo (300 mg of corn-starch) in two different days and cou...

A lack of exercise leads to being overweight or obese affecting regional brain structure and functional connectivity associated with impaired cognitive function and dementia. In recent decades, several studies of healthy individuals suggest that adiposity may also produce negative independent effects on the brain. We aimed to investigate the relati...

The purpose of the present study was to assess the accommodative response and pupillary dynamics while reading passages with different text-background color combinations on an LCD screen. Twenty healthy young adults read fourteen 2-min passages designed with fourteen different color combinations between text and background, while the accommodative...

Significance: The use of blood flow restriction allows to obtain beneficial physical adaptions when combined with low-intensity exercise, or even when used alone. We found that using blood flow restriction may be a potential strategy to avoid intraocular pressure and ocular perfusion pressure fluctuations provoked by strength and endurance training...

SIGNIFICANCE: Attention deficit/hyperactivity disorder (ADHD) is characterized by oculomotor abnormalities. However, the eye movement pattern of children with ADHD during reading has yet to be fully determined. This investigation provides novel insights into the altered eye movement pattern during oral reading of non-medicated children with pure AD...

Purpose: Assessing binocular accommodative facility (BAF) enables the evaluation of the interaction between the accommodative and vergence systems, which is relevant for the diagnosis of accommodative and binocular disorders. However, the tests used to assess BAF present methodological caveats (e.g., lack of objective control, vergence demands and...

Purpose: This study aimed to determine the impact of holding weight corresponding to the 10% and 20% of participants´ body weight during 5-minutes on intraocular pressure (IOP) and anterior eye biometrics. Methods: Eighteen healthy young adults grabbed two jugs with comfort-grip handles, which were filled with water in order to achieve the desirab...

Purpose: To investigate the acute effects of bench press sets leading to muscular failure with different loads on intraocular pressure (IOP) and ocular perfusion pressure (OPP). Study design: A randomized experimental study. Methods: Seventeen physically active young males performed four resistance training sets of bench press to muscular failure...

Significance: Attention-deficit/hyperactivity disorder (ADHD) has been commonly associated with alterations in visual perception. However, the individual behavior of visual perceptual skills and its relationship with different comorbidities remain unknown. Purpose: The purpose of this study was to examine whether visual perceptual skills are imp...

Purpose/Aim: To assess the changes in anterior eye segment biometrics and intraocular pressure during and after wearing swimming goggles. Materials and methods: Anterior segment biometry and intraocular pressure were assessed in twenty healthy young adults (22.2 ± 4.7 years) during the wearing of a drilled swimming goggle. The central corneal thic...

This study evaluated the time-on-task effect of a sustained attention task on the accommodative response, explored the link between ocular accommodation, cardiac autonomic regulation and behavioral performance, and tested the inter-session repeatability of these results by performing the same experimental procedure on different days. The accommodat...

Background: The deterioration of the integrity of binocular vision has a detrimental effect on fine visuomotor skills, however, its impact on sports performance remains unknown. We tested the influence of four viewing conditions (binocular viewing, monocular viewing, binocular viewing with monocular blur, and binocular viewing with binocular blur)...

Objectives: To evaluate the intraocular pressure (IOP) behaviour during a 1-minute period of isometric physical effort and the immediate 1-minute of recovery in the mid thigh clean pull and squat exercises at three different intensities. Methods: Twenty physically active individuals performed the isometric mid-thigh clean pull and squat exercises...

´Aniseikonia has demonstrated to deteriorate the binocular function, however its impact on the accommodative response remains unknown. The present study aimed to analyze the effects of artificially-induced aniseikonia, using afocal magnifiers, on the dynamics of the accommodative response. The magnitude and variability of the accommodative response...

We aimed to evaluate the acute effect of caffeine ingestion on the dynamics of ocular accommodation while performing a sustained attention task, as well as to compare the possible differences between low and high caffeine consumers. In this placebo-controlled, double-blind, balanced crossover study, twenty-one volunteers (10 low caffeine consumers...

Objectives: This study aimed to assess the effect of the breathing pattern during resistance training on intraocular pressure (IOP). Methods: Twenty physically active collegiate students (7 women and 13 men) performed sets of 10 repetitions against the 10-RM (repetition maximum) load during the back-squat and biceps-curl exercises following 3 diff...

Significance: The present study may be of relevance in the understanding of the accommodative response depending on the type of optical correction used. Our results are discussed due to its possible implications in myopia progression and visual fatigue. Purpose: The accommodative response has been investigated due to its possible relationship with...

Background: Caffeine has a well-established effect on intraocular pressure (IOP), and ocular perfusion pressure (OPP), however, the possible differences between low and high caffeine consumers remain unknown. Methods: In this placebo-controlled, double-blind, balanced crossover study, 40 healthy individuals were divided in low (n = 21) and high (n...

Objectives: We compared the impact of a maximal treadmill test on intraocular pressure (IOP) and ocular perfusion pressure (OPP) between trained and untrained individuals. Methods: Based on the maximal aerobic capacity (relative VO2 max), 31 military helicopter pilots were divided in groups of trained (n=16; VO2 max = 57.06±1.66) and untrained (n=...

Background: Surgeons’ overload is one of the main causes of medical errors that might compromise patient safety. Due to the drawbacks of current options to monitor surgeons’ load, new, sensitive, and objective indices of task (over)load need to be considered and tested. In non-health-care scenarios, intraocular pressure (IOP) has been proved to be...

Background: The execution of resistance exercise against heavy loads promotes an acute intraocular pressure (IOP) rise, which has detrimental effects on ocular health. However, the effect of load on the IOP behavior during exercise remains unknown due to technical limitations. Hypotheses: IOP monitoring during isometric squat exercise permits as...

Purpose: The present study aimed (1) to examine the impact of two high-intensity interval training (HIIT) protocols differing in exercise intensity (low-intensity and high-intensity) on the dynamic accommodative response (AR), and (2) to elucidate whether the ocular accommodation changes are associated with the function of the autonomic nervous sys...

Statement of significance: Our data demonstrates that intraocular pressure is sensitive to anxiety manipulation in sport scenarios, specifically in a basketball free throws task. The present outcomes may be of special relevance due to its practical advantages for the objective control of athletes´ anxiety levels. Purpose: Athletes experience high...

Purpose: We aimed (1) to test the acute impact of two high-intensity interval-training (HIIT) protocols differing in the level of effort on intraocular pressure (IOP) responses, and (2) to elucidate whether the IOP responses differ between men and women. Methods: Twenty-four physically active collegiate (12 men and 12 women) performed three protoco...

Background: We aimed to evaluate the influence of the level of effort during four basic resistance exercises leading to muscular failure on intraocular pressure (IOP) and ocular perfusion (OPP), as well as the role of exercise type and sex. Methods: Twenty-five young adults (12 women) performed 10 repetitions against their 10-RM (repetition maximu...

Purpose: Attention-deficit/hyperactivity disorder (ADHD) is one of the most common paediatric neurobehavioral disorders causing multiple functional impairments in children. Based on the relationship between the neural system that controls attention and ocular dynamics, the present study compares the magnitude and variability of accommodation betwee...

We aimed to test the effects of mental (i.e., executive) load during a dual physical-mental task on ratings of perceived exertion (RPE), affective valence, and arousal. The protocol included two dual physical-mental tasks with matched physical demands but different executive demands (2-back and oddball), carried out on different days. The whole pro...

Purpose: To determinate the long-term effect of a cycle ergometer sprint training program against heavy and light resistances on baseline intraocular pressure (IOP), and on the acute IOP response to cycling sprints. Methods: Twenty-seven physically active males were randomly assigned to a heavy loads group (HLG, n=9), low loads group (LLG, n=9), a...

Purpose/Aim: The execution of strength exercises has demonstrated to increase the intraocular pressure (IOP) levels, and it may have a negative impact on the ocular health. We aimed to explore the influence of fitness level on the acute intraocular pressure (IOP) response to strength exercises performed under different loading conditions, as well a...

Introduction: Previous studies have shown links of body composition and fitness measures with brain structure, as well as with different aspects of emotional adjustment and well-being. However, the possible role of trait emotion-regulation success in the relationship between fitness/body composition and emotion-related subcortical structures have...

Purpose: The purposes of this study were to (a) investigate the effect of physical effort (cycling for 60 min at 60 ± 5% of individually computed reserve heart-rate capacity), combined with 2 different levels of cognitive demand (2-back, oddball), on intraocular pressure (IOP) and subjective judgments of perceived exertion (ratings of perceived ex...

Background: This study aimed to determine the effect of two basic strength exercises with progressive loads on intraocular pressure (IOP). Methods: seventeen (out of 20 recruited) physically active male military officers (46 ± 4.77 years) performed the jump squat and the ballistic bench press exercises, in counterbalanced order, with four and five...

Intraocular pressure (IOP) has been investigated as a possible objective index of mental stressors. Here, we ass