Brien Holden Vision Institute

PurposeThis study explored potential effects of time of day and light filters on the ocular response to 1‐h myopic defocus and associated changes in melatonin.MethodsTwenty healthy myopic adults (mean age ± SD: 25.9 ± 3.9 years; spherical equivalent: −4.12 ± 1.00 D) participated in this study. Eight 1‐h visits, alternating between morning (9:00–11:00 h) and afternoon (15:00–17:00 h) were randomly scheduled on eight non‐consecutive days. Ocular measurements (axial length and choroidal thickness) of the right eye were taken at both the beginning and the end of each visit, following saliva sample collection for melatonin assessment. Two contact lenses were compared: single vision (control) and extended‐depth‐of‐focus (+2.25 D myopic defocus), in combination with three sets of light filters (blue‐pass, red‐pass and neutral density filters).ResultsAxial length elongated in the morning under three of the four conditions, with blue‐pass filters being the exception; no significant changes were detected in the afternoon except for the elongation with red‐pass filters. Both time of day and filters demonstrated significant effects on 1‐h axial length change (both p < 0.001; interaction of filter and timing, p < 0.001). The combination of blue‐pass filters and defocus showed an overall significant protective effect against axial elongation (p = 0.04). Melatonin concentration was influenced by time (p = 0.01), with concentration levels decreasing in the morning with neutral density and blue‐pass filters but remaining unchanged in the absence of blue light (with red‐pass filters). Choroidal thickness changes were not significant across all conditions.ConclusionsThis study demonstrates the impact of time‐of‐day and wavelength‐specific light exposure on axial length changes and melatonin levels. The protective effect of blue‐pass filters combined with myopic defocus highlights the potential of spectral light manipulation for myopia control. Further research is needed to investigate long‐term effects and validate these findings in real‐world settings.

As myopia research expands in scope and complexity, the International Myopia Institute (IMI) continues to provide timely, evidence-based consensus guidance through its biennial white papers and digests. The IMI 2025 Digest delivers targeted updates in areas identified for revision since the previous digest: definitions and classification of myopia, clinical management guidelines, risk factors, accommodation and binocular vision, experimental models, and onset and progression in young adults. A major focus is the evolving concept of pre-myopia, including a refined understanding of hyperopic reserve as a predictive marker, population-specific thresholds, and the distinction between risk and predictive factors. Emerging evidence supports earlier identification and targeted interventions during the pre-myopic phase to delay onset. Clinical management updates highlight that delaying onset by even 1 year may have greater lifetime benefit than multiple years of progression control. Other updates address the limited causal inference of many current risk factor studies, new molecular insights from experimental models, and evidence that a subset of young adults, particularly with high myopia, continue to progress at meaningful rates. Collectively, the IMI 2025 Digest underscores the importance of proactive, individualized myopia care, equipping clinicians with current, evidence-based guidance while supporting continued research and innovation.

PurposeTo provide a more sophisticated explanation of the optics involved when retinal ‘shadows’ are seen in scanning laser ophthalmoscopic images during the wear of multisegment and diffusion optic spectacle lenses.MethodsImages were recorded with a system that uses a scanning broad line fundus imaging principle in participants with undilated pupils wearing a multisegment spectacle lens. The live infra‐red preview display of the system was also acquired during image recording. Ray‐tracing and image simulations were performed, assuming a Maxwellian illumination system in which a source was refracted first through a lens and then through a model of a multisegment spectacle lens focused onto the pupil of an eye model and hence to the retina. A detector surface was positioned slightly in front of the retina to record the irradiation distribution. The light source was varied from 0.1 μm to 1.8 mm in diameter to investigate the effect of light source size on retinal irradiation distribution.ResultsThe retinal shadow pattern was visible on the live infra‐red preview display, as reported previously. However, the recorded images of the retina do not exhibit the same shadow pattern. The simulations predict that the circular shadows corresponding to lenslet positions become progressively less discernible with increasing light source size.ConclusionAn explanation is provided for the shadows on retinal images due to multisegment lenses, which may be observable under certain illumination conditions.

To assess the repeatability of lipid layer thickness (LLT) measurement using the LipiView® interferometer after daily disposable contact lens (CL) wear and correlation with ocular comfort in soft contact lens wearers. A prospective study was conducted over two consecutive months, wherein CL wearers (n = 20) wore either Somofilcon A or Verofilcon A daily disposable CLs in a crossover design, switching lenses after 1 month. The pre-corneal tear film LLT was measured at the end of each month after CLs had been worn for at least 6 h. Using the LipiView® interferometer, three measurements of the LLT (average, maximum and minimum) were recorded. Subjects' symptoms were evaluated with the Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) and correlations sought between post-lens pre-corneal tear film LLT and symptoms. The average, maximum and minimum intraclass correlation coefficients (ICC) of LLT measurements at baseline were 0.57, 0.39 and 0.66, respectively, indicating poor (ICC < 0.4) to moderate (≥0.4, <0.75) repeatability. Coefficients of repeatability (CR) were 20.4, 24.8 and 20.8, respectively. After daily disposable CL wear, the ICC values were 0.66, 0.72 and 0.63 (indicating moderate repeatability), with CR values of 25.7, 32.0 and 23.3, respectively. Although all the ICC values of the pre-corneal LLT increased after daily disposable lens wear indicating improved repeatability, the CR values also increased, indicating larger spread of data. However, in both cases, these increases were not significantly different from baseline. There were no significant differences in pre-corneal LLT between the two lens types and no significant correlation with comfort scores (baseline: r = -0.11, p = 0.67; Verofilcon A lenses: r = 0.19, p = 0.45; Somofilcon A lenses r = 0.13, p = 0.62) for either lens. The repeatability of average, maximum and minimum LLT measurements performed by LipiView remained stable during CL wear. There was no significant correlation between LLT and comfort scores.

BackgroundUncorrected refractive error (URE) is a readily treatable cause of visual impairment (VI). This study provides updated estimates of global and regional vision loss due to URE, presenting temporal change for VISION 2020MethodsData from population-based eye disease surveys from 1980–2018 were collected. Hierarchical models estimated prevalence (95% uncertainty intervals [UI]) of blindness (presenting visual acuity (VA) < 3/60) and moderate-to-severe vision impairment (MSVI; 3/60 ≤ presenting VA < 6/18) caused by URE, stratified by age, sex, region, and year. Near VI prevalence from uncorrected presbyopia was defined as presenting near VA < N6/N8 at 40 cm when best-corrected distance (VA ≥ 6/12).ResultsIn 2020, 3.7 million people (95%UI 3.10–4.29) were blind and 157 million (140–176) had MSVI due to URE, a 21.8% increase in blindness and 72.0% increase in MSVI since 2000. Age-standardised prevalence of URE blindness and MSVI decreased by 30.5% (30.7–30.3) and 2.4% (2.6–2.2) respectively during this time. In 2020, South Asia GBD super-region had the highest 50+ years age-standardised URE blindness (0.33% (0.26–0.40%)) and MSVI (10.3% (8.82–12.10%)) rates. The age-standardized ratio of women to men for URE blindness was 1.05:1.00 in 2020 and 1.03:1.00 in 2000. An estimated 419 million (295–562) people 50+ had near VI from uncorrected presbyopia, a +75.3% (74.6–76.0) increase from 2000ConclusionsThe number of cases of VI from URE substantively grew, even as age-standardised prevalence fell, since 2000, with a continued disproportionate burden by region and sex. Global population ageing will increase this burden, highlighting urgent need for novel approaches to refractive service delivery.

The prevalence of myopia in Scandinavia tends to be lower than in other parts of the world. This study aimed to investigate the incidence of myopia and its predictors in Swedish children to characterise this trend. A 2-year longitudinal study was conducted following a cohort of schoolchildren aged 8-16 years. Myopia was defined as a spherical equivalent refraction (SER) ≤ -0.50 D. The study enrolled 128 participants, 70 (55%) females with a mean age of 12.0 years (SD = 2.4). The cumulative incidence of myopia during the follow-up period was 5.5%, and the incidence rate of myopia was 3.2 cases per 100 person-years. Participants with myopia at baseline exhibited a faster increase in refractive error during the follow-up period. Likewise, participants with two myopic parents exhibited a more marked change towards myopia, regardless of their initial refractive error. In the current study, similar to prevalence, the incidence of myopia was low when compared with other parts of the world. These results lead us to formulate a new hypothesis that the normal emmetropisation process may be protected by low educational pressure practised in Sweden during early childhood. Further research is necessary to test this new hypothesis.

ObjectivesTo estimate global and regional trends from 2000 to 2020 of the number of persons visually impaired by glaucoma and their proportion of the total number of vision-impaired individuals.MethodsA systematic review and meta-analysis of published population studies and grey literature from 2000 to 2020 was carried out to estimate global and regional trends in number of people with vision loss due to glaucoma. Moderate or severe vision loss (MSVI) was defined as visual acuity of 6/60 or better but <6/18 (moderate) and visual acuity of 3/60 or better but <6/60 (severe vision loss). Blindness was defined as presenting visual acuity <3/60.ResultsGlobally, in 2020, 3.61 million people were blind and nearly 4.14 million were visually impaired by glaucoma. Glaucoma accounted for 8.39% (95% uncertainty intervals [UIs]: 6.54, 10.29) of all blindness and 1.41% (95% UI: 1.10, 1.75) of all MSVI. Regionally, the highest proportion of blindness relating to glaucoma was found in high-income countries (26.12% [95% UI: 20.72, 32.09]), while the region with the highest age-standardized prevalence of glaucoma-related blindness and MSVI was Sub-Saharan Africa. Between 2000 and 2020, global age-standardized prevalence of glaucoma-related blindness among adults ≥50 years decreased by 26.06% among males (95% UI: 25.87, 26.24), and by 21.75% among females (95% UI: 21.54, 21.96), while MSVI due to glaucoma increased by 3.7% among males (95% UI: 3.42, 3.98), and by 7.3% in females (95% UI: 7.01, 7.59).ConclusionsWithin the last two decades, glaucoma has remained a major cause of blindness globally and regionally.

Surveys in 2015 and 2019 identified a high level of eye care practitioner concern/activity about myopia, but the majority still prescribed single vision interventions to young myopes. This research aimed to provide updated information. A self-administered, internet-based questionnaire was distributed in 13 languages, through professional bodies to eye care practitioners globally. The questions examined awareness of increasing myopia prevalence, perceived efficacy and adoption of available strategies, and reasons for not adopting specific strategies. Of the 3195 respondents, practitioners' concern about the increasing frequency of pediatric myopia in their practices differed between continents (P < 0.001), being significantly higher in Asia (9.0 ± 1.5 of 10) than other continents (range 7.7-8.2; P ≤ 0.001). Overall, combination therapy was perceived by practitioners to be the most effective method of myopia control, followed by orthokeratology and pharmaceutical approaches. The least effective perceived methods were single vision distance undercorrection, spectacles and contact lenses, as well as bifocal spectacles. Practitioners rated their activity in myopia control between (6.6 ± 2.9 in South America to 7.9 ± 1.2/2.2 in Australasia and Asia). Single-vision spectacles are still the most prescribed option for progressing young myopia (32.2%), but this has decreased since 2019, and myopia control spectacles (15.2%), myopia control contact lenses (8.7%) and combination therapy (4.0%) are growing in popularity. More practitioners across the globe are practicing myopia control, but there are still significant differences between and within continents. Practitioners reported that embracing myopia control enhanced patient loyalty, increasing practice revenue and improving job satisfaction.

BackgroundTo explore the relationship between outdoor time and academic performance among school-aged children.MethodsThis study was designed as a cross-sectional study. Data were derived from a school-based prospective children myopia intervention study (STORM). Outdoor time was recorded by self-developed algorithm-validated wristwatches in real-time and calculated as the cumulative average of 10 months. The academic performance was recorded and provided by the participating schools and further standardized. Other information was collected using an online standardized questionnaire. Mixed-effects model and B-Spline method were used to investigate the association between time spent on different types of daily activity, including outdoor activity and academic performance.ResultsA total of 3291 children with mean age 9.25 years were included in the final analysis. Overall, outdoor time was associated with academic performance in a non-linear manner; specifically, not exceeding 2.3 h per day, outdoor time was positively associated with academic performance; exceeding 2.3 h per day, this association became non-significant. Likewise, daily sleep duration and out-of-school learning time were associated with academic performance in a non-linear manner, resulting in turning points of 11.3 and 1.4 h per day, respectively. Separate analysis showed that outdoor time and sleep duration but not out-of-school learning time were positively associated with academic performance in Chinese, mathematics and English.ConclusionOutdoor time, sleep duration and out-of-school learning time were associated with academic performance in a non-linear manner. Promotion of outdoor time may not negatively impact on academic performance.Trial registrationOur study was registered in ClinicalTrials.gov (Identifier: NCT02980445).