Search

This study aimed 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 sprints of 6 seconds against 3–4 different resistances separated by 3 minutes of rest. The IOP was measured on 9 occasions (1) prior to the warm-up, (2) after the warm-up, (3–7) every 6 minutes during the low-intensity cycling task, and (8–9) 5 and 10 minutes after the cycling task. Low-intensity aerobic exercise had a lowering effect on IOP, being the beneficial effect more accentuated and prolonged in the High-fit group (IOP reduction compared to baseline lasted 30 minutes) than in the Low-fit group (IOP was only reduced at 6 minutes of exercise compared to baseline). Participants´ sex had no effect on the IOP behaviour at any time point (p = 0.453). These findings indicate that individuals who need to reduce IOP levels (i.e., glaucoma patients or those at risk) should increase or maintain a high fitness level to benefit more from the IOP lowering effect during low-intensity aerobic exercises. [ABSTRACT FROM AUTHOR]

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; 24.1 ± 4.2 years). Two sessions were conducted. The 10RM load was determined in the first session. The second session consisted of 10RM under three BFR conditions (no-BFR, 40%-BFR, and 60%-BFR) that were applied in random order. IOP was measured before each condition, immediately after each repetition, and after 1 minute of passive recovery. A two-way repeated-measures ANOVA (restriction type [no-BFR, 40%-BFR, and 60%-BFR] x measurement point [basal, repetitions 1-10, and recovery]) was applied on the IOP measurements. Results: A significant main effect of the BFR condition (p = .022, np² = 0.21) was observed due to the significantly higher mean IOP values for the 60%-BFR (19.0 ± 0.7 mmHg) compared to the no-BFR (18.0 ± 0.8 mmHg; p = .048, dunb = 1.30). Non-significant differences with a large effect size were reached between 60%-BFR and 40%-BFR (18.1 ± 0.8 mmHg; p = .081, dunb = 1.16) and between no-BFR and 40%-BFR (p = .686, dunb = 0.18). IOP increased approximately 3-4 mmHg from baseline to the last repetition. Conclusions: Low-pressure BFR (40%-BFR) in combination with moderate-load (10RM load) resistance exercise could be an effective and safe strength training strategy while avoiding IOP peaks associated with heavy-load resistance exercises. These findings incorporate novel insights into the most effective exercise strategies in individuals who need to maintain stable IOP levels (e.g., glaucoma patients). [ABSTRACT FROM AUTHOR]

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 Filtering Face Piece 2 (FFP2) masks, during exercise practice has demonstrated to affect several physiological measures. This study was aimed at assessing the intraocular pressure (IOP) behaviour during the execution of the dynamic and isometric biceps-curl exercise with a surgical and FFP2 face mask. Twenty two physically active young adults performed sets of 10 repetitions against the 10-RM (repetition maximum) load and 1-minute isometric effort against a load 15% lower than the 10-RM load with the FFP2 and surgical mask and without any mask. A total of six exercise sets (3 experimental conditions [FFP2, surgical and control] × 2 exercise modalities) were performed. A rebound tonometer was used to measure IOP before, during (10 measurements), and after (30-seconds of passive recovery) each training set. At rest, there were not statistically significant IOP differences (p = 0.222). During dynamic exercise, there was a progressive IOP rise (p < 0.001), and a higher IOP response with the FFP2 than without the mask (corrected p-value = 0.003). For the isometric exercise, there was a greater IOP response as a function of accumulated effort (p < 0.001), which was dependent of the face mask used (FFP2> surgical>control; corrected p-values< 0.01). The FFP2 masks cause a heightened IOP response during the execution of dynamic and isometric biceps-curl exercise, suggesting that, when possible, glaucoma patients should limit the use of FFP2 masks during resistance training. [ABSTRACT FROM AUTHOR]

Dual-focus soft contact lenses are effective in slowing myopia progression; however, their influence on near work-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 single-vision soft contact lenses, which provides relevant information for better understanding the impact of using this optical design on the accommodative function. NITM has been proposed as a myogenic factor, although it is a matter of debate by the scientific community. The main objective of this study was to assess the short-term effect of wearing dual-focus soft contact lenses for myopia control on the steady-state accommodative response and NITM. Twenty-four young myope adults wore, on two different days, dual-focus and single-vision soft contact lenses, while the accommodative response was dynamically measured with an open-field autorefractor during the execution of the NITM task. The shift and the time required to recover baseline levels in the refractive state after performing the 5-min near task (20 cm) were the main dependent variables. We found a lower magnitude of accommodation during the execution of the near task with the dual-focus in comparison to the single-vision soft contact lenses (p < 0.001). There was a lower initial NITM with the dual-focus when compared to the single-vision lenses (corrected p-value = 0.003, Cohen's d = 0.68), but no statistically significant differences were observed for decay duration (p = 0.984). Dual-focus soft contact lens wear causes a reduced accommodative response during a near task, and an initial small myopic shift at distance after a 5-min period of near viewing. The current findings may help to understand the mechanisms involved in myopia control with this optical strategy. [ABSTRACT FROM AUTHOR]

There is some controversy about the utility of prescribing blue-blocking filters to mitigate digital eye strain. We found that using 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. There are some claims that blue-blocking (B-B) filters may be effective in reducing symptoms and signs of digital eye strain. However, recent studies have suggested that there is no sufficient evidence to support their use. This study assessed the short-term effects of a commercially available, B-B filter on orbicularis oculi (OO) muscle activity and symptoms of digital eye strain during the execution of a 30-min reading tas. Twenty-three healthy young adults (22.9 ± 3.2 years of age) performed two reading tasks from a computer screen with or without a B-B filter on two different days. OO muscle activity was recorded by surface electromyography 4–5, 9–10, 14–15, 19–20, 24–25 and 29–30 min into the trial. Participants reported their perceived levels of visual discomfort and activation before and after completing the reading task. A Bayesian analysis favoured the null hypothesis that there was no change in OO muscle activity with or without using the B-B filter (Bayes Factor01 [BF01] = 7.08). Regarding symptomatology, the analysis favoured the time model that reading increased visual fatigue and discomfort but reduced activation levels (BF01 < 0.33 in all cases). However, our data did not support the alternative model that using B-B filter affected these visual symptoms. The B-B filter did not alter OO muscle activity or visual symptomatology significantly during the execution of a 30-min reading task in asymptomatic subjects. These findings support the idea that B-B filters do not attenuate signs and symptoms of digital eye strain. [ABSTRACT FROM AUTHOR]

Clinical Relevance Background: Steady-state accommodation is frequently evaluated with open-field autorefractors; however there is no consensus regarding the optimal test duration. Our results allow us to standardise the procedure followed for the assessment of the steady-state accommodative response in clinical and laboratory settings and may be of great relevance in time-constrained situations. Background: The present study aims to determine the optimal recording time to assess the magnitude and variability of the accommodative response with a binocular open-field autorefractor. Methods: The steady-state accommodative response of 84 healthy undergraduate students was dynamically measured using the Grand Seiko WAM-5500 autorefractor at 500 cm, 40 cm and 20 cm for 90 s while participants maintained focus on a stationary target. We examined the reliability and level of agreement between four time intervals (the first 10-s, 30-s, 60-s and 90-s) at three accommodative demands (0.2D, 2.5D and 5D). Results: The magnitude of accommodation showed an excellent level of reliability (intraclass correlation coefficient [ICC]> 0.90) for the comparisons between the 90-s, 60-s and 30-s time intervals at the three viewing distances tested. However, when including the 10-s interval, there was a moderate reduction of the reliability indices and an increase of the mean difference between two time intervals (intra-class correlation [ICC] ranging from 0.89 to 0.97; and ESs ranging from 0.16 to 0.42). For the variability of accommodation, we observed an excellent reliability for the comparisons of the 90-s and 60-s measures at the three accommodative demands (ICC: 0.95–0.96), whereas for the rest of comparisons we observed from moderate to good levels of reliability. Conclusion: Our data indicate that of 30-s and 60-s are enough to accurately assess the magnitude and variability of the accommodative response with the WAM-5500 autorefractor, respectively. [ABSTRACT FROM AUTHOR]

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 clinical implications.Background: This placebo-controlled, double-blind, balanced crossover study aimed to assess the acute effects of caffeine ingestion on the frequency and precision of the binocular accommodative facility.Methods: Twenty university students (21.9 ± 3.4 years) ingested a capsule of caffeine (4 mg/kg) or placebo (300 mg of corn-starch) on two different days and counterbalanced order. The binocular accommodative facility was objectively assessed, using the WAM-5500 binocular open-field autorefractometer, after 60 min of capsule ingestion (caffeine/placebo). Perceived levels of activation was also assessed in each experimental condition.Results: The ingestion of a single administration of caffeine (~ 4 mg/kg) causes an increase in the number of cycles performed per minute (p = 0.023, Cohen's d = 0.55), whereas no effects were observed for the mean magnitude of accommodative change between the far and near targets (p = 0.794), and the percentage of incorrect cycles of accommodation and dis-accommodation (p = 0.271 and 0.396, respectively). Participants reported a perceived level of activation of 6.8 ± 1.5 and 7.6 ± 1.8 in the placebo and caffeine conditions, respectively (p = 0.059).Conclusion: Caffeine intake improves quantitative, but not qualitative, measures of accommodative facility. These results corroborate the impact of caffeine on visual function and suggest that this ergogenic effect of caffeine may be used to enhance visual performance in applied situations. [ABSTRACT FROM AUTHOR]

Recent technological advances have permitted to objectively record 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 test, in comparison to the ±2.00 DS lens flippers. Fifty-six individuals took part in this study (36 healthy young adults [24.4 ± 3.2 years] and 20 children [12.2 ± 0.4 years]). Participants randomly performed the 2Q-AF and the ±2.00 DS lens flipper tests. For the 2Q-AF test, a binocular open-field autorefractor was used to record the magnitude of accommodative response during a 60-sec period, while participants repeatedly changed fixation from a 5 m to a 40 cm chart when clarity of vision was achieved at each level. Due to the advantages of the proposed method, we have determined the number of cycles and the 2Q-AF score, with the latter also considering the accuracy of changes in accommodation. A standard procedure was followed for the ±2.00 DS flipper test. Our data exhibited a moderate association between the number of cycles with the ±2.00 DS lens flippers and the number of cycles in the 2Q-AF test in the group of young adults (p =.005, r = 0.46 [0.15–0.68]) and children (p =.007, r = 0.58 [0.19–0.81]), whereas a stronger relationship was observed when considering the number of cycles with the ±2.00 DS lens flippers and the 2Q-AF score (young adults: p <.001, r = 0.83 [0.69–0.91]; and children: p <.001, r = 0.78 [0.52–0.91]). The current findings show that the 2Q-AF test is a valid method for accommodative facility assessment, as suggested by its good levels of reliability and validity. This method allows to examine the accommodative facility in qualitative terms and solve most of the limitations associated with the ±2.00 DS lens flipper test. [ABSTRACT FROM AUTHOR]

Appropriate visual function is paramount to ensuring adequate driving performance and road safety. Here, we examined the influence of sudden artificially-impaired binocular vision on driving performance using a car simulator. Twenty-four young drivers (mean age 22.42±3.19 years) drove under three different visual conditions (natural driving, monocular blur, and monocular occlusion) through three different traffic environments with low, medium, and high levels of complexity (highway, rural, and city, respectively). We assessed their driving performance, perceived level of task complexity, and subjectively-experienced road safety. Furthermore, as a manipulation check, we also evaluated the drivers' cardiac vagal responses, as a well-known index of task complexity. The sudden deterioration of binocular vision caused unsafe driving behaviours (distance out of the road and maximum breaking intensity) in the most complex traffic environments. Specific self-regulatory strategies (i.e. increased cardiac vagal responses) and subjective responses corroborated these results. [ABSTRACT FROM AUTHOR]

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. One hundred and seventy-six sport science students (102 men and 74 women) performed a maximal isometric handgrip test with the dominant and non-dominant hands. A rebound tonometer was used to measure IOP before effort, during effort, and immediately after performing the handgrip test. Men and women were divided based on their handgrip strength in low- and high-strength groups using a median split analysis. There was an acute IOP rise during effort, returning to baseline levels immediately after exercise cessation (P <.001, ηp2 = 0.79). A greater increase in IOP during the execution of the handgrip test was observed for the dominant-hand compared to the non-dominant hand (P =.004, d = 0.30) and for men compared to women (P =.001, d = 0.90). The main effect of strength level did not reach statistical significance (P =.266). The IOP rise associated with a maximal isometric handgrip effort is affected by the participants´ sex (men > women) and hand dominance (dominant hand > non-dominant hand), but not on strength levels. These findings need to be corroborated in glaucoma patients. [ABSTRACT FROM AUTHOR]

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. 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 counterbalanced order. After 30 min of capsule ingestion, we objectively measured the accuracy and variability of accommodation, and pupil size using the WAM-5500 binocular open-field autorefractometer for 2 min at each of the six viewing distances (5 m, 50 cm, 40 cm, 33 cm, 25 cm, and 20 cm). Subjective levels of activation to check the effectiveness of caffeine/placebo manipulation were also reported. We found that after 30 min of caffeine/placebo ingestion, participant perceived higher levels of activation in the caffeine condition (p =.047, Cohen´s d = 0.48). Caffeine consumption induced a statistically significant dilator effect on pupil size (p =.011, η2 = 0.271), and reduced variability of accommodative response (p =.027, η2 = 0.211). However, no differences were obtained for the accuracy of accommodation (p =.321). Our data suggest that caffeine consumption reduced the variability of accommodative response and induced pupil dilation. Nevertheless, the accuracy of accommodation was insensitive to caffeine intake. These findings may be explained by the bidirectional relationship between ocular functioning and the nervous system´s state of activation. [ABSTRACT FROM AUTHOR]

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 20 healthy young adults (22.2 ± 4.7 years) during the wearing of a drilled swimming goggle. The central corneal thickness, anterior chamber depth, anterior chamber volume, and anterior chamber angle, using the Pentacam rotating Scheimpflug camera (Oculus Optikgerate GmbH, Wetzlar, Germany), and intraocular pressure, using a rebound tonometer, were obtained before, at 2, 3.5, and 5 min of wearing swimming goggle, just after removal, as well as after 5 min of recovery. Results: During swimming goggles wear, there was a significant corneal thinning (54.8 ± 41.1 µm, p <.001, ƞp2 = 0.532), iridocorneal angle reduction (2.6 ± 2.6 degrees, p <.001, ƞp2 = 0.241) and intraocular pressure elevation (4.0 ± 1.9 mmHg, p <.001, ƞp2 = 0.530). These changes returned to baseline values immediately after swimming goggle removal (corrected p-value <0.05 in all cases). No significant effects of swimming goggles use were observed for anterior chamber depth and anterior chamber volume. Conclusions: Wearing swimming goggles leads to acute corneal thinning, iridocorneal angle reduction, and intraocular pressure elevation. These findings may be of special relevance for individuals with corneal ectasias, as well as for individuals at high risk of glaucoma onset or progression. [ABSTRACT FROM AUTHOR]

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 image size alterations), limiting its external validity. This study aimed to (i) develop a new objective method to quantitatively and qualitatively evaluate the BAF in free-viewing conditions, and explore its validity by the comparison with the Hart Chart test, and (ii) assess the inter-session reliability of the proposed method. Methods: 33 healthy young adults took part in this study. We used a binocular open-field autorefractor to continuously assess the magnitude of accommodative response during a 60-sec period, while participants repeatedly changed fixation from a far to a near chart when clarity of vision was achieved at each level. Accommodative response data were used to characterize the BAF measurement in quantitative (number of cycles) and qualitative terms (percentage of times that correctly accommodating or dis-accommodating in each level of accommodation as well as the magnitude of the accommodative change). Results: Our data revealed that the new proposed method accurately counted the number of cycles per minute when compared with the Hart Chart test (p =.23, ES = 0.02; mean difference = 0.18 ± 0.85). The inter-session reliability of the proposed method was demonstrated to be excellent (Pearson r and intraclass correlation coefficient: 0.95 to 0.98) for the parameters obtained with the BAF test. Conclusions: The present outcomes evidence that the proposed objective method allows to accurately assess the frequency and precision of BAF by the combination of the classical Hart Chart test and a binocular open-field autorefractometer. Our findings may be of relevance for the diagnosis and treatment of accommodative and binocular disorders. [ABSTRACT FROM AUTHOR]

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. Twenty-four physically active collegiate (12 men and 12 women) performed three protocols: low-fatigue HIIT (eight 30-m sprints with 60-s of rest), high-fatigue HIIT (eight 30-m sprints with 30-s of rest), and control (walking). IOP was taken at baseline, after sprints and recovery by rebound tonometry. Our data revealed an acute IOP reduction during both HIIT protocols compared to the control condition (effect size [ES]:0.81-1.65). The differences between both HIIT protocols were generally negligible (ES<0.30), however, the reduction of IOP was moderately higher for the low-fatigue HIIT protocol after the 7th (ES: 0.67) and 8th (ES: 0.74) sprints. Women showed a more prominent lowering effect on IOP during the control condition (ES: 0.42-1.02), and during the two first sprints of both HIIT protocols (ES: 0.54-1.03). These findings highlight that a time-efficient HIIT protocol may acutely reduce IOP levels, while low-fatigue HIIT protocol could be recommended since it induced a higher reduction on IOP than the high-fatigue HIIT protocol. [ABSTRACT FROM AUTHOR]

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 system during stimulus processing, as measured by the heart rate variability (HRV). Methods: Twenty physically active university students (9 women; age = 23.9 ± 3.3 years) were tested on three separate sessions. The lag of accommodation and the root mean square of successive R-R interval differences (RMSSD) parameter of HRV were obtained at the beginning and at the end of each testing session, while one of the following protocols was applied in a randomized order between the measurements, low-intensity HIIT (8 sprints with 60 s of rest), high-intensity HIIT (8 sprints with 30 s of rest), and Control (walking for 8 min). Results: Our data demonstrated a higher lag of accommodation after the high-intensity HIIT compared to the low-intensity HIIT (p = 0.006, d = 0.798) and control (p = 0.007, d = 0.741), but no significant differences were observed between the low-intensity HIIT protocol and control condition (p = 0.598, d = 0.12). As expected, lower HRV values were observed with higher exercise intensity, but the changes of AR and HRV were not significantly correlated (p > 0.05 in all cases). Conclusions: The present findings indicate that the acute effects of exercise on ocular accommodation depend on exercise intensity, showing that highly demanding physical effort induces a greater lag of accommodation, which may be of relevance when performing near activities after physical efforts. [ABSTRACT FROM AUTHOR]

This study 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 tasks with matched physical demands but different executive demands (2-back and oddball), carried out on different days. The procedure was run twice to assess the sensitivity and stability of RPE, valence and arousal across the two trials. Linear mixed-effects analyses showed less positive valence (−0.44 points on average in a 1-9 scale; Rβ2 = 0.074 [CI90%, 0.052-0.098]), and heightened arousal (+0.13 points on average in a 1-9 scale; Rβ2 = 0.006 [CI90%, 0.001-0.015]), for the high executive load condition, but showed no effect of mental load on RPE. Separated analyses for the two task trials yielded best-fitting models that were identical across trials for RPE and valence, but not for arousal. Model fitting was improved by assuming a 1-level autoregressive covariance structure for all analyses. In conclusion, executive load during a dual physical-mental task modulates the emotional response to effort, but not RPE. The autoregressive covariance suggests that people tend to anchor estimates on prior ones, which imposes certain limits on scales' usability. [ABSTRACT FROM AUTHOR]

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 IOP response to strength exercises performed under different loading conditions, as well as to test whether the IOP responses differ between the bench press and jump squat when performed against the same relative loads. Materials and Methods: Forty military personnel males were divided in two subgroups (20 high-fit and 20 low-fit) based on their relative to body mass one-repetition maximum (1-RM). Participants performed an incremental loading test in the bench press and jump squat exercises, and IOP was assessed before and after each repetition by rebound tonometry. Results: IOP increased immediately after executing both exercises (p < 0.01 in both cases), being the magnitude of the IOP increment positively and linearly associated with the increment of the load in both groups (i.e., high-fit and low-fit) and in both exercises (R2 range: 0.81-1.00). Higher fitness level attenuated the IOP rise produced by both exercises (p < 0.01 in both cases). The bench press induced higher IOP increments than the jump squat for both groups at relative loads of ~50%1-RM and ~60%1-RM (p < 0.01 in all cases). Conclusions: These data indicate that IOP increases as a consequence of performing strength exercises, being the increment accentuated with the increase of the load and in the bench press compared to the jump squat exercise. Of special importance would be that the IOP responses were significantly reduced in high-fit individuals. These findings should be addressed in glaucoma patients. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM PUBLISHER]

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 exertion [RPE]), affect (Affective Valence subscale of the Self-Assessment Manikin [SAM]), and mental workload (National Aeronautics and Space Administration Task Load Index [NASA-TLX]); and (b) ascertain whether baseline IOP, measured before exercise, is associated with individual differences in subjective assessments of effort and affective response during exercise.Method: Seventeen participants (Mage = 23.28 ± 2.37 years) performed 2 physical/cognitive dual tasks, matched in physical demand but with different mental requirements (2-back, oddball). We assessed IOP before exercise, after 2 min of active recovery, and after 15 min of passive recovery, and we also collected RPE and SAM measures during the sessions (28 measurement points). We used NASA-TLX and cognitive performance as checks of the mental manipulation.Results: (a) Intraocular pressure increased after concomitant physical/mental effort, with the effect reaching statistical significance after the 2-back task (p = .002, d = 0.35) but not after the oddball condition (p = .092, d = 0.29). (b) Baseline IOP was associated with subjective sensitivity to effort and showed statistical significance for the oddball condition (p = .03, ƞp2 = .622) but not for the 2-back task (F < 1).Conclusions: Results suggest a relationship between IOP and physical/cognitive effort, which could have implications for the management of glaucoma. Additionally, a rapid measure of IOP could be used as a marker of individual effort sensitivity in applied settings. [ABSTRACT FROM AUTHOR]