Investigating the role of flight phase and task difficulty on low-time pilot performance, gaze dynamics and subjective situation awareness during simulated flight.

Gaze behaviour has been used as a proxy for information processing capabilities that underlie complex skill performance in real-world domains such as aviation. These processes are highly influenced by task requirements, expertise and can provide insight into situation awareness (SA). Little research has been done to examine the extent to which gaze behaviour, task performance and SA are impacted by various task manipulations within the confines of early-stage skill development. Accordingly, the current study aimed to understand the impact of task difficulty on landing performance, gaze behaviour and SA across different phases of flight. Twenty-four low-time (<300 hours) pilots completed simulated landing scenarios under visual flight rules conditions. Traditional gaze metrics, entropybased metrics, and blink rate provided meaningful insight about the extent to which information processing is modulated by flight phase and task difficulty. The results also suggested that gaze behavior changes compensated for increased task demands and minimized the impact on task performance. Dynamic gaze analyses were shown to be a robust measure of task difficulty and pilot flight hours. Recommendations for the effective implementation of gaze behaviour metrics and their utility in examining information processing changes are discussed.

An Urgent Call for Concussion Incidence Measures in Para Sport for Athletes with Vision Impairment: A Narrative Review.

Concussion in para athletes with vision impairment (VI) is poorly understood. Recently published studies have suggested that athletes with VI may be more likely to sustain sport-related concussions compared to non-disabled athletes and athletes with other impairment types. There is a critical need for objective concussion incidence measures to determine concussion injury rates and risks more accurately. The aim of this review was to examine the limited available evidence of concussion incidence rates across six different para sports for athletes with VI and encourage the future collection of concussion incidence data and the adoption of injury prevention strategies in VI para sport. A literature search was conducted using four unique databases, which formed the basis of this narrative review. Injury prevention strategies such as modifying sport rules, introducing protective equipment, and incorporating additional safety measures into the field of play have been introduced sporadically, but the effectiveness of most strategies remains unknown. More prospective, sport-specific research examining mechanisms of injury and risk factors for concussion injuries in athletes with VI in both training and competition is needed. This research will help inform the development of targeted injury prevention strategies to reduce the likelihood of concussion for athletes with VI.

Comparing paediatric optometric vision care in Canada over a 14-year period.

PURPOSE: In Canada, teaching in paediatric eye care has increased in the past decade both within the optometry curriculum and as continuing education to optometrists. Paediatric vision care guidelines have also been established by North American optometric associations. This study examined whether this exposure was associated with changes in paediatric eye care in Canada over a 14-year period. METHODS: Canadian optometrists were invited to participate in an anonymous 35-item survey in 2007 and 2021. The surveys sought to investigate optometrist's recommendations for first eye examinations, the number of paediatric patients seen in a typical week and preparedness to provide eye examinations to children. Response frequencies were determined for each survey item. RESULTS: Across Canada, 133/1000 (13.3%) and 261/~6419 (~4.1%) optometrists responded to the survey in 2007 and 2021, respectively. No significant difference was found in the number of years practicing, days per week in practice and total number of patients seen per week. The modal age optometrists recommended children be seen for their first eye examination changed from 3-4 years in 2007 (53%) to 6-12 months in 2021 (61%). In 2007, 87% of respondents provided eye examinations to children <2 years, increasing to 94% in 2021 (p = 0.02). Despite a reduction in the recommended age between the two survey years, the most frequent age children were seen for their first eye examination was 3-4 years (30% in both surveys) and the most common age seen in a typical week remained unchanged (4-6 years-56% 2007; 66% 2021). CONCLUSION: Although optometrists' willingness to provide paediatric eye care increased over the past 14 years, the number of children seen in a typical week did not change. Barriers to determine why more children are not being seen at an earlier age need to be investigated.

The effects of task difficulty on gaze behaviour during landing with visual flight rules in low-time pilots.

Eye movements have been used to examine the cognitive function of pilots and understand how information processing abilities impact performance. Traditional and advanced measures of gaze behaviour effectively reflect changes in cognitive load, situational awareness, and expert-novice differences. However, the extent to which gaze behaviour changes during the early stages of skill development has yet to be addressed. The current study investigated the impact of task difficulty on gaze behaviour in low-time pilots (N=18) while they completed simulated landing scenarios. An increase in task difficulty resulted in longer fixation of the runway, and a reduction in the stationary gaze entropy (gaze dispersion) and gaze transition entropy (sequence complexity). These findings suggest that pilots' gaze became less complex and more focused on fewer areas of interest when task difficulty increased. Additionally, a novel approach to identify and track instances when pilots restrict their attention outside the cockpit (i.e., gaze tunneling) was explored and shown to be sensitive to changes in task difficulty. Altogether, the gaze-related metrics used in the present study provide valuable information for assessing pilots gaze behaviour and help further understand how gaze contributes to better performance in low-time pilots.

Investigation of Camera-Free Eye-Tracking Glasses Compared to a Video-Based System.

Technological advances in eye-tracking have resulted in lightweight, portable solutions that are capable of capturing eye movements beyond laboratory settings. Eye-tracking devices have typically relied on heavier, video-based systems to detect pupil and corneal reflections. Advances in mobile eye-tracking technology could facilitate research and its application in ecological settings; more traditional laboratory research methods are able to be modified and transferred to real-world scenarios. One recent technology, the AdHawk MindLink, introduced a novel camera-free system embedded in typical eyeglass frames. This paper evaluates the AdHawk MindLink by comparing the eye-tracking recordings with a research "gold standard", the EyeLink II. By concurrently capturing data from both eyes, we compare the capability of each eye tracker to quantify metrics from fixation, saccade, and smooth pursuit tasks-typical elements in eye movement research-across a sample of 13 adults. The MindLink system was capable of capturing fixation stability within a radius of less than 0.5∘, estimating horizontal saccade amplitudes with an accuracy of 0.04∘± 2.3∘, vertical saccade amplitudes with an accuracy of 0.32∘± 2.3∘, and smooth pursuit speeds with an accuracy of 0.5 to 3∘s, depending on the pursuit speed. While the performance of the MindLink system in measuring fixation stability, saccade amplitude, and smooth pursuit eye movements were slightly inferior to the video-based system, MindLink provides sufficient gaze-tracking capabilities for dynamic settings and experiments.

Validation of the Waterloo Differential Visual Acuity Test (WatDAT) and Comparison With Existing Pediatric Tests of Visual Acuity.

Purpose: The new Waterloo Differential Acuity Test (WatDAT) is designed to allow recognition visual acuity (VA) measurement in children before they can typically undertake matching tests. The study purpose was to validate WatDAT in adults with normal and reduced VA. Methods: Eighty adults (18 to <40 years of age) participated (32 normal VA, 12 reduced VA, and 36 simulated reduced VA). Monocular VA was measured on two occasions in random order for WatDAT (versions with 3 and 5 distractors for Faces and Patti Pics house among circles), Lea Symbols, Kay Pictures and Patti Pics matching tests, Teller Acuity Cards, Cardiff Acuity Test, and Early Treatment Diabetic Retinopathy Study (ETDRS) letter chart. Pediatric tests were validated against ETDRS using limits of agreement (LoA), sensitivity, and specificity. The LoA for repeatability were also determined. Results: WatDAT showed minimal bias compared with ETDRS, and LoAs, which were similar to pediatric matching tests (0.241-0.250). Both preferential looking tests showed higher bias and LoAs than ETDRS. Matching tests showed good agreement with ETDRS, except for Kay Pictures and Lea Uncrowded test, which overestimated VA. WatDAT showed high sensitivity (>0.96) and specificity (>0.79), which improved with criterion adjustment and were significantly higher than for the preferential looking tests. LoA for repeatability for WatDAT 3 Faces and WatDAT 5 Faces were comparable with the ETDRS. Conclusions: WatDAT demonstrates good agreement and repeatability compared with the gold-standard ETDRS letter chart, and performed better than preferential looking tests, the alternative until a child can undertake a matching VA test. Translational Relevance: Good validity of the Waterloo Differential Acuity Test was demonstrated in adults as a first step to showing its potential for detecting childhood visual disorders.

Trust and Access: Eye Information-seeking Practices and Preferences among Canadians.

SIGNIFICANCE: This study highlights the value that the public places on obtaining trusted and accessible health-related information and their preference for obtaining it from their health care practitioners. Previous research has not been specific to Canadians or vision. Findings can be used to increase eye health literacy and eye care utilization. PURPOSE: Canadians underuse eye care and underestimate the occurrence of asymptomatic eye disease. This study explored eye information-seeking practices and preferences among a group of Canadians. METHODS: Using snowball sampling, a 28-item online survey collected respondent perceptions about their eye and health information-seeking practices and preferences. Questions examined electronic device access, information source use, and demographics. Two open-ended questions examined information-seeking practices and preferences. Respondents were at least 18 years old and living in Canada. Individuals working in eye care were excluded. Response frequencies and z scores were computed. Written comments were assessed using content analysis. RESULTS: Respondents searched for less eye than health information ( z scores ≥ 2.25, P < .05). For eye and health information, primary care providers were the used and preferred source, and reliance on Internet searches was greater than desired. Trust and access drove information-seeking practices. Respondent comments suggested that a hierarchy of trust operates across My Health Team, My Network, and My External Sources, with a persistent threat posed by Discredited Sources. Access to information sources seemed mediated by enablers (Convenience and Accessible Features) and barriers (Unreachable Health Team and Absent Systems). Eye information was seen as more specialized and harder to find. There was a high regard for health care practitioners who provide their patients with curated trusted information. CONCLUSIONS: These Canadians value trusted and accessible health-related information. They prefer eye and health information from their health care practitioners and value when their health team provides online curated information, particularly regarding eyes.

What the Canadian public (mis)understands about eyes and eye care.

CLINICAL RELEVANCE: Inadequate public knowledge about eyes and eye care poses avoidable risks to vision-related quality of life. BACKGROUND: This study of eye care knowledge among Canadians extends earlier findings from focus groups. METHODS: Perceptions about eyes and eye care were sought using a 21-item online survey and snowball sampling. Inclusion criteria were living in Canada and being at least 18-years old; eye care professionals and staff were excluded. Response frequencies were converted to percentages, with eye condition items analysed according to 'expected' or 'unexpected' eye impacts. Proportions selecting these impacts or 'unsure' were determined. RESULTS: There were 424 respondents: 83.0% aged 20-65 years and 69.6% female. Mismatches existed between perceived recommendations and behaviours for booking eye exams: within two years (86.7% vs. 68.4%) and symptom-driven (3.3% vs. 13.0%). First eye exams after age one year were deemed appropriate by 43.6%. Few respondents associated glaucoma with no symptoms (6.0%) or amblyopia with blurred vision (13.5%). A notable proportion incorrectly related tunnel vision with age-related macular degeneration (AMD, 36.8%) and cataract (21.9%). Identifying all 'expected' responses was unlikely for glaucoma (1.9%), amblyopia (6.7%), and cataract (12.0%). Most respondents identified no 'expected' effects for glaucoma (63.8%) and AMD (46.2%) and some 'expected' effects for cataract (59.5%) and amblyopia (72.6%). Selecting 'unsure' was 9-10 times more common among respondents choosing no 'expected' impacts than those choosing some. Awareness of thyroid-associated eye disease was lowest (32.4%) of seven conditions. Respondents were most likely to consult optometrists for routine eye exams, eye disease, diabetes eye checks and blurred vision but family physicians for red eyes and sore eyes. Respondents typically paid for their eye exams and eyewear but wanted government to pay. CONCLUSION: Vision-threatening knowledge gaps and misinformation about eyes and eye care among Canadian respondents highlight the need for accessible, targeted public education.

Measuring recognition visual acuity in young children - testability with the Waterloo Differential Acuity Test (WatDAT).

CLINICAL RELEVANCE: Visual acuity measurement is important for the detection and monitoring of eye disorders. Developing accurate and sensitive visual acuity tests suitable for young children is therefore desirable. BACKGROUND: Recognition or form visual acuity (VA), which is measured with matching in children aged 3 years and up, is more sensitive for detecting visual deficits compared to resolution VA. The Waterloo Differential Acuity Test (WatDAT) is a proposed recognition VA test using the concept of identifying the "odd one out" among distractors. The WatDAT is expected to be cognitively easier than matching tests and therefore may be used in younger children. The purpose of this study is to investigate the testability of the WatDAT paradigm in children aged 12-36 months, and to determine the optimum format and number of distractors. METHODS: Fifty-one typically-developing children aged 12-36 months participated in the study. Data for Patti Pics (PP) and Face targets (FT) were collected for formats with 3, 4 and 5 distractors. The targets were presented binocularly on a computer touch screen at 30 cm. The task was to touch the face among identical non-faces or a house among circles. Following initial training, there were 5 presentations for each distractor format. Testability was defined as correctly identifying at least 4/5 presentations and was also determined for uncrowded PP symbols using matching. RESULTS: Of participants aged 18-36 months, 87% could perform the WatDAT PP targets with 3 distractors compared to 68% for the FT, while 48% could perform matching with PP. The testability for FT increased to 85% for children ≥22 months. Younger children showed lower testability. For the 3 distractor format, PP targets gave 9% testability in children 12 to <18 months, and FT gave a testability of 16% in children 12 to <22 months. CONCLUSION: WatDAT testability is higher than matching VA tests. This indicates that the newly developed WatDAT has potential for measuring recognition VA in children 18 months and older.

Shape judgments in natural scenes: Convexity biases versus stereopsis.

Determining the relief of upcoming terrain is critical to locomotion over rough or uneven ground. Given the significant contribution of stereopsis to perceived surface shape, it should play a crucial role in determining the shape of ground surfaces. The aim of this series of experiments was to evaluate the relative contribution of monocular and binocular depth cues to judgments of ground relief. To accomplish this goal, we simulated a depth discrimination task using naturalistic imagery. Stimuli consisted of a stereoscopically rendered grassy terrain with a central mound or a dip with varying height. We measured thresholds for discrimination of the direction of the depth offset. To determine the relationship between relief discrimination and measures of stereopsis, we used two stereoacuity tasks performed under the same viewing conditions. To assess the impact of ambiguous two-dimensional shading cues on depth judgments in our terrain task, we manipulated the intensity of the shading (low and high). Our results show that observers reliably discriminated ground reliefs as small as 20 cm at a viewing distance of 9.1 m. As the shading was intensified, a large proportion of observers (30%) exhibited a strong convexity bias, even when stereopsis indicated a concave depression. This finding suggests that there are significant individual differences in the reliance on assumptions of surface curvature that must be considered in experimental conditions. In impoverished viewing environments with limiting depth cues, these convexity biases could persist in judgments of ground relief, especially when shading cues are highly salient.

Athletes Demonstrate Superior Dynamic Visual Acuity.

SIGNIFICANCE: Athletes exhibit better dynamic visual acuity (DVA) compared with nonathletes, whereas action video game players (VGPs) perform more similarly to controls despite having similar static visual acuity and refractive errors. The differences in DVA between groups were not related to differences in static visual acuity, refractive error, or smooth pursuit gain. PURPOSE: The purpose of the study was to examine whether athletes and VGPs have superior DVA than controls (nonathletes, nongamers). METHODS: Forty-six participants (15 athletes, 11 VGPs, 20 controls) aged 21.7 years (standard deviation, 2.8 years) were recruited. Participants were emmetropic with equivalent monocular and binocular static visual acuity between groups. Dynamic visual acuity was assessed using predictable (horizontal) and unpredictable (random) motion targets at velocities of 5, 10, 20, and 30°/s. Smooth pursuit eye movements were assessed using a horizontal motion step-ramp stimulus at the same speeds. This study was pre-registered with the Center for Open Science (https://osf.io/eu7qc). RESULTS: At 30°/s, there were significant main effects of group (F = 4.762, P = .01) and motion type (F = 9.538, P = .004). Tukey post hoc analysis for groups indicated that athletes performed better than did the control group (t = -2.919, P < .02). An omnibus (group × motion type × speed) repeated measures ANOVA showed a main effect of speed (F = 110.137, P < .001) and a speed × motion-type interaction (F = 27.825, P < .001). Dynamic visual acuity decreased as speed increased, and the slope of the change was greater for random than for horizontal motion. Smooth pursuit gains were not significantly different between groups (P > .05). CONCLUSIONS: Athletes have superior dynamic visual acuity performance compared with controls at 30°/s. This between-group difference cannot be fully explained by differences in smooth pursuit eye movements and therefore may reflect other differences between the groups.

Changing vergence function in persons with Parkinson's disease and convergence insufficiency.

Individuals with Parkinson's disease and convergence insufficiency were assigned vergence training. After two months, average positive fusional vergence increased and average near point of convergence decreased. Vergence can be improved with training in persons with Parkinson's disease who also have convergence insufficiency.

Differential visual acuity - A new approach to measuring visual acuity / Agudeza visual diferencial - Nuevo método para medir la agudeza visual

BACKGROUND: A novel type of acuity measurement, which we refer to as 'differential acuity', requires the observer to identify one unique target among three others which are identical. This is a proof of concept study aimed to determine if differential acuity is equivalent to standard measures of recognition acuity. METHODS: To create a range of visual acuity, vision was optically blurred in sixteen adults with normal visual acuity. Visual acuity was then measured with the differential acuity targets in both crowded and uncrowded format, and compared with standard ETDRS acuity or with singly presented letters and uncrowded letters were analysed separately. RESULTS: The visual acuity results for crowded and uncrowded letters were analysed separately. Repeated measures analysis of variance showed that when a crowded Sloan C had to be differentiated from three crowded Os (CvsO), the results were not significantly different from ETDRS acuity or from naming one of four letters presented centrally (Name4) (p < 0.05). Similar results were found for uncrowded letters - the C versus O and Name4 gave similar visual acuity. The 95% limits of agreement between the naming and C versus O differential acuity measures were between 0.17 and 0.27 logMAR. CONCLUSION: From this proof of concept study we conclude that differential acuity gives similar results to the ETDRS chart in adults. We infer that the comparable but cognitively simpler differential visual acuity task could be applied in clinical settings for young children or patients with developmental delay who cannot respond by naming or matching

ANTECEDENTES: Un nuevo tipo de medición de la agudeza, al que denominaremos 'agudeza diferencial, requiere que el observador identifique un único objetivo entre tres otros objetivos idénticos. Se trata de una prueba de estudio de concepto, que trata de determinar si la agudeza diferencial es equivalente a las mediciones estándar de agudeza de reconocimiento. MÉTODOS: Para crear un rango de agudeza visual, se degradó ópticamente la visión en dieciséis adultos con agudeza visual normal. A continuación se midió la agudeza visual con los objetivos de agudeza diferencial, tanto en formato aglomerado como no aglomerado, y comparándose con la agudeza ETDRS estándar, o con letras presentadas de manera única, analizándose las letras no aglomeradas separadamente. Los análisis de mediciones repetidas de varianza reflejaron que cuando una C Sloan aglomerada debía diferenciarse de tres O aglomeradas (CvsO), los resultados no eran significativamente diferentes de la agudeza ETDRS, o de nombrar una de las cuatro letras presentadas centralmente (Nombrar4) (p < 0,05). Se encontraron resultados similares para las letras no aglomeradas - C versus O - y Nombre4 arrojó una agudeza visual similar. Los límites de acuerdo del 95% de las mediciones de agudeza diferencial, entre nombrar y C versus O, se situaron entre 0,17 y 0,27 logMAR. CONCLUSIÓN: A partir de este estudio de prueba de concepto concluimos que la agudeza diferencial arroja resultados similares al cuadro ETDRS en adultos. Podemos inferir que podría aplicarse la tarea de agudeza visual diferencial, comparable pero cognitivamente más simple, al entorno clínico para jóvenes o pacientes con retraso del desarrollo cognitivo, y que no pueden responder mediante denominación o emparejamiento

Contributions of Stereopsis and Aviation Experience to Simulated Rotary Wing Altitude Estimation.

OBJECTIVE: We examined the contribution of binocular vision and experience to performance on a simulated helicopter flight task. BACKGROUND: Although there is a long history of research on the role of binocular vision and stereopsis in aviation, there is no consensus on its operational relevance. This work addresses this using a naturalistic task in a virtual environment. METHOD: Four high-resolution stereoscopic terrain types were viewed monocularly and binocularly. In separate experiments, we evaluated performance of undergraduate students and military aircrew on a simulated low hover altitude judgment task. Observers were asked to judge the distance between a virtual helicopter skid and the ground plane. RESULTS: Our results show that for both groups, altitude judgments are more accurate in the binocular viewing condition than in the monocular condition. However, in the monocular condition, aircrew were more accurate than undergraduate observers in estimating height of the skid above the ground. CONCLUSION: At simulated altitudes of 5 ft (1.5 m) or less, binocular vision provides a significant advantage for estimation of the depth separation between the landing skid and the ground, regardless of relevant operational experience. However, when binocular cues are unavailable aircrew outperform undergraduate observers, a result that likely reflects the impact of training on the ability to interpret monocular depth cues.

Motivators and deterrents for seeking eye care in a Canadian region.

BACKGROUND: Motivators and deterrents for seeking eye care in a Canadian setting were sought using a qualitative study. Provincial deregulation of eyewear dispensing in 2010 allows consumers to order eyewear without an optical prescription, thus eliminating a potential motivator for obtaining an eye examination. METHODS: Convenience sampling was used to obtain 25 members of the public who contributed to one of seven focus groups that were facilitated, audiotaped, anonymised and transcribed. Participants completed a demographic questionnaire. Focus group data analysis employed grounded theory and theme saturation determined the number of focus groups. RESULTS: Nine men and 16 women participated, ranging in age from 18 to 71 years (mean 41.5; median 40.0). Three main themes were identified as influencers for seeking eye care: priority; advice; and capacity. Priority served as a motivator ('lived experience', 'symptoms', and 'habit') and deterrent ('test distress', 'asymptomatic', 'don't know' and 'other priorities'). Advice was a motivator ('professional' and 'family/friends'), while capacity was a motivator ('insurance') and deterrent ('cost'). CONCLUSION: The motivators and deterrents of seeking eye care in these focus groups were framed by three themes. Key findings not reported previously included the motivators of 'habit', 'advice' and 'insurance' and the potential deterrent of 'test distress'. These factors should be added to other previously reported motivators and deterrents in further exploration of Canadian eye-care seeking behaviours. Such knowledge is needed to develop strategies for improving eye-care literacy in Canada. This is particularly important because eyewear deregulation and/or online eye examinations may encourage members of the public to bypass comprehensive eye care without fully understanding the implications of this decision for their health and wellness.

Differential visual acuity - A new approach to measuring visual acuity.

BACKGROUND: A novel type of acuity measurement, which we refer to as 'differential acuity', requires the observer to identify one unique target among three others which are identical. This is a proof of concept study aimed to determine if differential acuity is equivalent to standard measures of recognition acuity. METHODS: To create a range of visual acuity, vision was optically blurred in sixteen adults with normal visual acuity. Visual acuity was then measured with the differential acuity targets in both crowded and uncrowded format, and compared with standard ETDRS acuity or with singly presented letters and uncrowded letters were analysed separately. RESULTS: The visual acuity results for crowded and uncrowded letters were analysed separately. Repeated measures analysis of variance showed that when a crowded Sloan C had to be differentiated from three crowded Os (CvsO), the results were not significantly different from ETDRS acuity or from naming one of four letters presented centrally (Name4) (p<0.05). Similar results were found for uncrowded letters - the C versus O and Name4 gave similar visual acuity. The 95% limits of agreement between the naming and C versus O differential acuity measures were between 0.17 and 0.27 logMAR. CONCLUSION: From this proof of concept study we conclude that differential acuity gives similar results to the ETDRS chart in adults. We infer that the comparable but cognitively simpler differential visual acuity task could be applied in clinical settings for young children or patients with developmental delay who cannot respond by naming or matching.

Refractive error magnitude and variability: Relation to age / Magnitud y variabilidad del error refractivo: relación con la edad

Purpose: To investigate mean ocular refraction (MOR) and astigmatism, over the human age range and compare severity of refractive error to earlier studies from clinical populations having large age ranges. Methods: For this descriptive study patient age, refractive error and history of surgery affecting refraction were abstracted from the Waterloo Eye Study database (WatES). Average MOR, standard deviation of MOR and astigmatism were assessed in relation to age. Refractive distributions for developmental age groups were determined. MOR standard deviation relative to average MOR was evaluated. Data from earlier clinically based studies with similar age ranges were compared to WatES. Results: Right eye refractive errors were available for 5933 patients with no history of surgery affecting refraction. Average MOR varied with age. Children < 1 yr of age were the most hyperopic (+1.79 D) and the highest magnitude of myopia was found at 27 yrs (-2.86 D). MOR distributions were leptokurtic, and negatively skewed. The mode varied with age group. MOR variability increased with increasing myopia. Average astigmatism increased gradually to age 60 after which it increased at a faster rate. By 85+ years it was 1.25 D. J0 power vector became increasingly negative with age. J45 power vector values remained close to zero but variability increased at approximately 70 years. In relation to comparable earlier studies, WatES data were most myopic. Conclusions: Mean ocular refraction and refractive error distribution vary with age. The highest magnitude of myopia is found in young adults. Similar to prevalence, the severity of myopia also appears to have increased since 1931

Objetivo: Estudiar la refracción ocular media (MOR) y el astigmatismo a lo largo del rango de la vida humana, y comparar la magnitud del error refractivo con estudios previos sobre poblaciones clínicas con rangos de edad amplios. Métodos: Para este estudio descriptivo, se extrajeron de la base de datos Waterloo Eye Study (WatES) la edad del paciente, el error refractivo y el historial de cirugía con repercusión en la refracción. Se evaluaron la MOR media, la desviación estándar de MOR y el astigmatismo con relación a la edad. Se calcularon las distribuciones refractivas para los grupos de edad evolutiva. Se evaluó la desviación estándar de MOR con respecto a MOR media. Se compararon los datos de los estudios clínicos previos con los rangos de edad similares de WatES. Resultados: Se dispuso de los errores refractivos del ojo derecho de 5.933 pacientes sin historial de cirugía con repercusión en la refracción. La MOR media sufrió variaciones con la edad. Los niños con edad <1 año reflejaron mayor hipermetropía (+1,79 D), encontrándose el mayor valor de miopía a los 27 años (-2,86 D). Las distribuciones de MOR fueron leptocúrticas, y negativamente sesgadas. La moda varió con el grupo de edad. La variabilidad de MOR se incrementó al aumentar la miopía. El astigmatismo medio aumentó gradualmente hasta los 60 años, pasados los cuales se incrementó a mayor velocidad. A los 85 años, o más, su valor fue de 1,25D. El vector de potencia J0 se modificó hacia valores más negativos con la edad. Los valores del vector de potencia J45 fueron cercanos a 0, aunque su variabilidad se incrementó a los 70 años, aproximadamente. Con relación a los estudios previos comparables, los datos WatES fueron más miópicos. Conclusiones: La refracción ocular media y la distribución del error refractivo varían con la edad. La mayor magnitud de la miopía se encontró en los adultos jóvenes. Al igual que la prevalencia, la gravedad de la miopía parece haberse incrementado desde 1931