CLINICAL RELEVANCE:A non-refractive approach for potential myopia management is introduced as spectacle films with opaque features, hypothesised to modulate retinal ganglion cell activity away from the baseline state of the eye. Visual performance of these spectacle films is currently unknown. BACKGROUND:The aim of this work is to compare the visual performance of spectacle films with opaque non-refractive features (test), MiYOSMART (control: MS), and single vision (control: SV) lenses. METHODS:This was a prospective, randomised, unmasked, cross-over study where 37 myopic adults (18-42 years) wore each lens for a minimum of 5 days. Subjective visual performance was assessed with a 1-10 numeric rating scale for clarity of vision, vision at night, vision when walking, and overall vision satisfaction and visual acuity (monocular at 6 m and binocular at 6 m and 40 cm). Willingness-to-purchase, based on vision and myopia efficacy, was assessed with a binary Yes/No response. RESULTS:Test and SV were rated higher than MS (p ≤ 0.005) for all subjective ratings, while SV was rated higher than test (p ≤ 0.02) for all ratings except vision when walking (p = 0.11). A higher proportion were willing to purchase both test and SV compared to MS based on vision (p ≤ 0.001), with no difference between test and SV (p = 0.20). A higher proportion were willing to purchase SV compared to MS based on myopia efficacy (p = 0.005), with no difference between test and either control (p > 0.06). SV was significantly better than MS for acuity at 40 cm (p = 0.004) with no differences between lenses for other acuity measurements (p > 0.1). CONCLUSIONS:Test offered better subjective visual performance than MS with higher proportions of participants willing to purchase based on vision. Test offered worse subjective visual performance than SV with no differences in willingness-to-purchase questions. SV offered better visual performance than MS and higher proportions of participants willing to purchase for vision or myopia management.

PURPOSE:To compare the visual performance (VP) of P.A.U.S.E. spectacle lenses (tests) against defocus incorporated multiple segments (DIMS; control). METHODS:This randomized, single-masked study included 48 participants aged 18-41 years who wore five tests (T1, T2, T4, T5, T6) and DIMS. VP was assessed through the full-lens and inferior treatment zone. Full-lens visual-acuity (VA) based measurements comprised monocular high- and low-contrast VA (HCVA/LCVA) at 6 m and binocular HCVA at 6 m and 40 cm. Assessments through the treatment zone comprised HCVA at 40 cm and subjective ratings (1-10 scale) of near vision-clarity and ease-of-reading. VP was assessed after 3 days of wear (full-lens) using subjective ratings of vision-clarity, night-vision, vision-while-walking, eyestrain, overall-vision-satisfaction, and willingness-to-purchase (yes/no: based on vision and myopia management efficacy). Analyses were performed using linear mixed models and the X2 test. Significance was set at 5%. RESULTS:Full-lens binocular HCVA at 40 cm was significantly better with three tests (T2, T4, T5) compared to DIMS (p ≤ 0.022), whereas there were no differences between any test and DIMS for monocular or binocular HCVA at 6 m (p > 0.5). Full-lens monocular LCVA at 6 m was significantly better with DIMS compared to T4 (p = 0.0057). Through the treatment zone, four tests (T2, T4, T5, T6) were significantly better than DIMS for binocular HCVA at 40 cm (p < 0.0001), near vision-clarity (p ≤ 0.0011) and ease-of-reading (p ≤ 0.0014). T2 was rated significantly higher than DIMS for night-vision (p = 0.0085) and overall-vision-satisfaction (p = 0.0495), whereas DIMS was rated higher than T1 for vision-clarity (p = 0.0001). There were no significant differences between DIMS and any test for other subjective ratings (p > 0.07), nor willingness-to-purchase based on vision (p > 0.2) or myopia management efficacy (p > 0.6). CONCLUSIONS:Most of the test lenses achieved better VP through the treatment zone compared to the DIMS control. T2 showed better overall VP compared to DIMS, whereas DIMS showed better overall VP compared to T1.

SIGNIFICANCE:Objective through-focus testing with phase alteration utilizing subelements technology indicates improvements in retinal image contrast across a range of retinal defocus. If validated in clinical trials, this approach may provide a better visual experience for wearers, potentially supporting compliance and myopia management outcomes. PURPOSE:This study aimed to evaluate the optical performance of modified axicons and modified light sword elements of phase alteration utilizing subelements lens design (test), compared with two defocus-based control lenslet designs, defocus incorporated multiple segments and highly aspheric lenslets using a calibrated benchtop model eye. METHODS:The through-focus optical performance of test and control lenses was evaluated. Individual subelements (Part I), and groups of elements (Part II) were assessed with 3 and 6 mm clear apertures, respectively. A Siemens star target images were captured across defocus ranging from -6.50 to +1.00 D in 0.25 D increments, repeated with 3-, 4-, and 5-mm pupils. Michelson contrast was calculated for each image and depth of focus values were obtained for spatial frequencies 15 to 22.5 cycles/degree. RESULTS:The phase alteration utilizing subelement lenses demonstrated a different depth of focus characteristics compared with both control lenses. In Part I, modified axicons (3.35 to 3.92 D) and modified light sword elements (3.32 to 3.77 D) showed a greater depth of focus across all spatial frequencies than the defocus incorporated multiple segments (p<0.05). The highly aspheric lenslets lenses showed a greater depth of focus for 15 and 17.5 cycles/degree targets (p>0.05) compared with the modified axicon. In Part II, modified axicons resulted in greater depth of focus compared with both control lenses. Similarly, modified light sword elements demonstrated a comparable or better depth of focus than both control lenses across most spatial frequencies, while both control lenses performed better with 15 and 17.5 cycles/degree targets (p<0.001). CONCLUSIONS:The model eye evaluation suggests that the phase alteration utilizing subelements spectacles can provide an extended depth of focus (EDOF) under controlled laboratory conditions, suggesting improved image contrast in front of the retina. These observations warrant further clinical investigation into visual performance and explore the potential of this technology in myopia management.

PURPOSE:The Spatio-Temporal Optical Phase (S.T.O.P.; nthalmic Pty Ltd) kit provides a dynamic optical cue using optical films on single-vision spectacles. This study assessed the efficacy of 2 S.T.O.P. kits (kits 1 and 2) in reducing myopia progression against single-vision spectacles without optical films (control group). DESIGN:Prospective, multi-site, parallel-group, double-masked randomized controlled trial. PARTICIPANTS:One hundred fifty-five participants completed the study (n = 50, 52, and 53 in the kit 1, kit 2, and control groups, respectively). METHODS:One hundred sixty eligible children 6 to 14 years of age with myopia of between -0.75 diopter (D) and -5.00 D and astigmatism of 1.50 D or less were enrolled at the Fudan University Eye and ENT Hospital and Tianjin Eye Hospital between December 2023 and February 2025. Participants were assigned randomly to wear kit 1, kit 2, or no optical films (control group). Axial length (AL) was measured at baseline, at dispensing, and at 1, 4, and 6 months after dispensing. Cycloplegic autorefraction was measured at baseline and 6 months after dispensing. Differences between the control and each test group for changes in AL and spherical-equivalent cycloplegic autorefraction were analyzed using linear mixed models in the intention-to-treat population. Differences in visual acuity (VA) and subjective ratings were also assessed. MAIN OUTCOME MEASURES:Change in AL from dispensing to the 6-month visit and change in spherical-equivalent cycloplegic autorefraction from baseline to the 6-month visit. RESULTS:After 6 months, both S.T.O.P. kit groups showed significantly less change in AL than the control group. The estimated least-square mean differences (95% confidence intervals) compared with control for AL were: kit 1, -0.091 (-0.131 to -0.051) mm and kit 2, -0.090 (-0.130 to -0.050) mm and for spherical-equivalent cycloplegic autorefraction were: kit 1, 0.135 (0.003 to 0.268) D and kit 2, 0.134 (0.001 to 0.267) D. No significant differences were found between groups for VA or any subjective rating. CONCLUSIONS:Both S.T.O.P. kit groups showed significantly less myopia progression compared with the control group while maintaining good visual performance. The S.T.O.P. kit's dynamic approach represents a promising strategy for myopia management. FINANCIAL DISCLOSURE(S):Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

SIGNIFICANCE:Contact lenses (CLs) utilizing opaque, nonrefractive features may purposefully modulate retinal ganglion cell activity away from the baseline activity. This is a nonrefractive mechanism that may reduce myopia progression. However, the visual performance of CLs with opaque features is unknown. PURPOSE:This study aimed to compare the visual performance and binocular/accommodative function of CLs with opaque features (test) against MiSight (control-1) and single-vision (control-2) CLs. METHODS:This was a prospective, randomized, unmasked, cross-over study where 35 myopic CL wearers (18 to 39 years) wore each design for at least 5 days. Visual performance was subjectively assessed using 1 to 10 numeric ratings comprising clarity of vision, lack of ghosting, vision when driving, overall vision satisfaction, and willingness to purchase (yes/no: based on vision and myopia efficacy). Visual acuity measurements comprised monocular and binocular high and low contrast visual acuity at 6 m, and binocular high contrast visual acuity at 70 and 40 cm. Binocular function was assessed using heterophorias at 3 m and 40 cm. Accommodative function was assessed using monocular accommodative facility (MAF) at 40 cm and dynamic monocular accommodative response (AR: 6 m, 70 cm, and 40 cm). RESULTS:Test was rated higher than control-1 (p<0.001) and control-2 was rated higher than test (p≤0.0052) for all subjective ratings. More participants were willing to purchase test compared with control-1 for vision and myopia efficacy (p<0.001), while there was no difference between test and control-2 for either question (p>0.7). Both controls were better than test for all acuity-based measurements (p≤0.0013). MAF at 40 cm was better with test compared with control-1 (p=0.010) and not different to control-2 (p>0.99). AR was higher with test than both controls at 70 cm (p<0.0001), higher than control-1 at 40 cm (p<0.0001), and not different to control-2 at 40 cm (p=0.12). There were no differences between CLs for AR at 6 m or heterophorias at 3 m or 40 cm (p>0.1). CONCLUSIONS:Compared with control-1, the test offered better visual performance, a higher proportion of participants willing to purchase, and better MAF. Compared with control-2, the test offered worse visual performance, but the proportion of participants willing to purchase was not different, and accommodative function was comparable.

OBJECTIVES:To assess the reliability of the liquid jet esthesiometer (LJA) for measurement of corneal sensitivity. METHODS:Two separate studies were conducted to assess intrasession repeatability (study 1) and intersession reproducibility (study 2) of corneal sensitivity measured using the LJA. Thirty participants (13 female and 17 male participants, age 23±6 years) participated in study 1 and another 30 (18 female and 12 male participants, 35±10 years) participated in study 2. For study 1, mechanical sensation threshold of the central cornea was measured three times on the same day, with a 30-min break between repeats. For study 2, central corneal sensation threshold was measured on five different days by one of eight randomly assigned examiners. RESULTS:Corneal sensation thresholds obtained in studies 1 and 2 were 2.3±1.0 and 2.5±1.2 μL, respectively. No significant differences between repeated measurements were obtained in either study ( P ≥0.19). Thresholds were lower (i.e., corneal sensitivity was higher) in female than male participants (2.1±1.0 vs. 2.7±0.9 μL in male participants, P =0.02) but were not affected by contact lens wear. Clinical reliability of the LJA was good for intrasession repeatability (coefficient of repeatability ±1.6 μL, intraclass correlation coefficient 0.74, within-subject coefficient of variation (CV W ) 24%) and moderate for intersession reproducibility (Coefficient of Reproducibility ±2.2 μL, CV W 32%). Measurement variability was independent of threshold level ( P =0.84). CONCLUSIONS:The LJA offers good clinical repeatability and is a reliable tool to measure corneal sensitivity in different population groups, regardless of stimulus thresholds. Day-to-day fluctuations in corneal sensitivity probably account for the relatively lower reproducibility.

The vast majority of soft contact lenses are today mass produced by a double-sided moulding process, ensuring relatively consistent quality and eliminating the need to measure every lens that comes out of production. Nevertheless, practitioners may still wish to occasionally measure lenses for identification purposes or to verify expected optical and material properties and geometric dimensions of lenses, which can be undertaken with reference to standard ISO 18369 set by the International Standards Organization. Optical properties that can be measured include power and power profiles, optical quality and scattering. Material properties that can be assessed include water content, modulus, wettability, surface friction, oxygen permeability and transmissibility, refractive index and dispersion, and spectral and luminous transmittance. Key lens geometric features are diameter, sagittal depth, thickness, radius of curvature and characteristics of the lens edge.

SIGNIFICANCE Spatio-Temporal Optical Phase technology utilizes film pairs containing optical elements applied to standard single-vision spectacle lenses. This technology provides a dynamic optical cue that may have efficacy in reducing the rate of myopia progression, but the visual performance of this technology is unknown. PURPOSE This study aimed to assess the visual performance of film pairs containing optical elements (tests) and a film pair with no optical elements (control). METHODS In this randomized, single-masked, bilateral wear study, 42 participants aged 18 to 40 years wore four test designs (E, F-1, G, and F-2) and the control. Subjective data (subjective ratings [1 to 10 scale]: clarity of vision [far-away, intermediate, near] and vision [at night, while walking, overall satisfaction], and willingness to purchase [yes/no response]) were collected after 3 days. Visual acuity (VA)–based measures (monocular high/low-contrast VA [6 m], contrast sensitivity [6 m], and binocular high-contrast VA [6 m and 40 cm]) were collected at dispensing. Visual acuity–based measures were also collected while wearing spectacles with no film. Analyses were performed using linear mixed models and the χ 2 test. Significance was set at 5%. RESULTS The control performed better than any test for all subjective ratings (mean differences, 1.6 to 3.1 units: p<0.001), willingness to purchase (p<0.001), and designs F-1 and F-2 for binocular high-contrast VA at 40 cm (p=0.001 and p=0.01, respectively). Clarity of vision was significantly worse with F-2 compared with F-1 and G (p<0.001 and p=0.02, respectively). There were no differences between tests for any other subjective rating (p>0.1), willingness to purchase (p=0.11), or any VA-based measure (p>0.08). There were no differences between control and spectacles with no film for any VA-based measure (p>0.08). CONCLUSIONS All four test film pairs reduced visual performance compared with control to a degree comparable with other myopia management devices. There was no difference in visual performance between three of the four test film pairs.

SIGNIFICANCE:Prolonged computer use may result in repeated stimulation of the ocular surface due to ocular dryness, potentially leading to alterations in its sensitivity. PURPOSE:This study aimed to evaluate the relationship between ocular symptoms and corneal sensitivity to cold and mechanical stimuli in computer users. METHODS:Fifty-two young (31 ± 6 years), frequent computer users, including symptomatic and asymptomatic users, participated in this study. Mechanical and cold sensation thresholds were determined at the central cornea of one randomly selected eye of each participant using the UNSW Liquid Jet Aesthesiometer. Ocular surface symptoms and digital eye strain were assessed using the Ocular Surface Disease Index, Ocular Comfort Index, Instant Ocular Symptom Survey, and Computer Vision Syndrome Questionnaire (CVS-Q). Associations between central corneal sensation thresholds and demographic variables, patterns of digital device use, and symptom scores were analyzed using Pearson (r) or Spearman (ρ) correlations and linear regression models. RESULTS:Age (ρ = 0.24), CVS-Q score (ρ = -0.33), CVS-Q dry eye score (ρ = -0.28), and mechanical sensation threshold (ρ = 0.63) were significantly associated with cold sensation threshold (p≤0.04). Conversely, there were no significant relationships with Ocular Surface Disease Index, Ocular Comfort Index, or Instant Ocular Symptom Survey or with other demographic variables (p≥0.34). In multiple linear regression models, age and mechanical sensation threshold were significant predictors of cold sensitivity (p=0.04 and p<0.001, respectively) (adjusted R2 = 0.459). There were no significant correlations between mechanical sensitivity and symptom scores (p≥0.09). CONCLUSIONS:Symptoms of digital eye strain, particularly those related to dry eye, were associated with higher corneal cold sensitivity. Corneal hypersensitivity to cold stimuli as a marker of ocular discomfort during computer use requires further investigation.

Objectives: The objective of this study was to compare the visual performance and binocular/accommodative function of two novel S.T.O.P. design (F2 and DT) contact lenses against MiSight when worn by myopic, young adults. Method: This was a prospective, randomized, cross-over, single-masked study. Each lens was worn daily wear with overnight peroxide disinfection for approximately 7 days. Visual performance was assessed with subjective ratings (0–100): clarity of vision and lack of ghosting (far away, intermediate, and near), vision when driving, overall vision satisfaction, and with monocular high-contrast and low-contrast visual acuity (HCVA/LCVA) at 6 m, binocular HCVA (6 m, 70 cm, 50 cm, and 40 cm), binocular LCVA (6 m and 70 cm). Binocular function was assessed with heterophorias (3 m and 40 cm). Accommodative function was assessed with monocular accommodative facility (AF: 40 cm) and dynamic monocular accommodative response (AR: 6 m, 70 cm, and 40 cm). Results: F2 was rated higher than MiSight for clarity of vision (near and intermediate) and lack-of-ghosting ( P <0.001), while MiSight was rated higher than DT for clarity of vision (near, P <0.001). MiSight was better than F2 and DT for monocular HCVA (6 m) and binocular HCVA (6 m and 40 cm, P ≤0.02), but the maximum difference was ≤2 letters. There were no differences between designs for heterophoria ( P =0.61) nor were there any differences between DT and MiSight for any accommodative measure ( P >0.1). F2 was higher for monocular-AF ( P =0.007) and lower for AR (70 cm and 40 cm; P ≤0.007) compared with MiSight. Conclusions: The visual performance and binocular/accommodative function of S.T.O.P. designs F2 and DT were comparable with MiSight. F2 outperformed MiSight in some aspects of subjective visual performance and monocular accommodative function.

PURPOSE:To investigate and evaluate the chromatic dispersion of various hydrogel and silicon hydrogel contact lens materials. METHODS:Eighteen different soft contact lens materials with high and low water content in lens power of -1.00 DS were measured by one operator at temperature of 20 °C ± 0.5° soaked in ISO standard phosphate-buffered saline (PBS) and in their respective packaging solutions (PS). An analogue Abbe refractometer (Model Zuzi 320, AUXILAB, S.L., Navarra, Spain) was used for refractive index (RI) measurements at 5 different wavelengths. All contact lenses were presented in a random and masked order to the operator. The Bland-Altman method with 95 % limits of agreement (LoA) and coefficient of repeatability (CoR) was used to characterise the repeatability of refractive index measurements. The Abbe numbers for each material were calculated by entering the measured and interpolated refractive indices into the Abbe number equation. One-way ANOVA analysis was used to test if there were significant differences between the 5 different wavelengths (470 nm-680 nm) within each material. An unpaired t-test was used to determine if there were differences in refractive index or dispersion between packaging solution and PBS results. RESULTS:Nelfilcon A (Dailies Aqua Comfort Plus) soaked in PS showed the best repeatability of all 18 examined soft contact lenses across all wavelengths with an average refractive index of 1.3848 for all 6 contact lenses with a standard deviation of 0.00064. The 95 % limits of agreement were between 1.3835 and 1.3860. The mean coefficient of repeatability for nelfilcon A was 0.00125. For contact lenses soaked in ISO Standard PBS comfilcon A (Biofinity) had the best repeatability. The average refractive index of all 6 contact lenses was 1.4041 with a standard deviation of 0.00031 and a coefficient of repeatability of 0.00060. The 95 % limits of agreement were between 1.4035 and 1.4047. The analysis with One-way ANOVA with multiple comparisons involving Holm-Sidak post-hoc, showed that there are significant differences (p < 0.001, Fratio = 376.2 between wavelengths and Fratio = 1559 between different refractive indices) in the refractive index of most common lens materials across the visible wavelength range. Based on unpaired t-test, there is no significant difference (p > 0.05) in the Abbe numbers of the tested lens materials whether they have been placed in the packaging solution or in standard PBS (p > 0.05, 95 % CI = -4.8070 to 5.8680, t = 0.2054). The Abbe numbers for the calculated contact lenses soaked in PS ranged between 43.7 and 89.9. For contact lenses stored in PBS the range was between 46.3 and 81.6. CONCLUSION:There is a good repeatability between repeated RI measurements taken from the same lens and from the same material. The significant differences between the refractive indices across the 5 different wavelengths showed the presence of chromatic dispersion in the 18 evaluated soft contact lens materials. Furthermore, it could be shown that there is no significant difference in dispersion whether the contact lenses are soaked in standard PBS or in their respective packaging solutions. With no other published data available as a reference, absolute accuracy of the calculated Abbe numbers remains to be confirmed, however, this study did confirm that significant chromatic dispersion exists in soft contact lens materials.

Purpose: To determine the effect of temperature on the accommodative response of non-human primate crystalline lenses during simulated accommodation.Methods: Eight lenses from 7 cynomolgus monkeys (Macaca fascicularis, ages: 4.5-7.3 years; post-mortem time: 17.0 & PLUSMN; 16.4 h) were mounted in a lens stretcher. Stretching experiments were performed on each lens at 24 C (room temperature), then the tissue was warmed to 35 C (intraocular temperature) and the stretching experiments were repeated. The lens diameter, thickness, anterior and posterior surface radii of curvature, optical power, and the stretching force (load) were measured at each stretch position and the linear optomechanical relationships were quantified: load-lens diameter, load-thickness, power-load, load-anterior radius, and load-posterior radius. The rate of change for each parameter was quantified by performing a linear regression. The slopes of the linear regressions were compared at the two temperatures using a paired sample t-test.Results: The average changes in the lens with stretching at 24 C and 35 C were: 3.07 & PLUSMN; 0.17 and 2.58 & PLUSMN; 0.15 for load-lens diameter (g/mm),-2.38 & PLUSMN; 0.20 and-2.00 & PLUSMN; 0.32 for load-thickness (g/mm),-13.35 & PLUSMN; 1.21 and-13.75 & PLUSMN; 1.26 for power-load (D/g), 0.41 & PLUSMN; 0.10 and 0.34 & PLUSMN; 0.05 for load-anterior radius of curvature (g/mm), and 1.35 & PLUSMN; 0.24 and 1.31 & PLUSMN; 0.35 for load-posterior radius of curvature (g/mm), respectively. The changes in load-diameter and load-thickness with lens stretching were significantly different for the two temperatures. Conclusions: Temperature influences the change in lens shape observed during simulated accommodation in nonhuman primate lenses. These results suggest that lens stretching experiments and other optomechanical measurement techniques on ex vivo crystalline lenses be conducted at 35 C and that the temperature of the tissue sample be documented and maintained constant to ensure repeatability.