This study evaluated the long-term myopia control effect and safety in children wearing Defocus Incorporated Multiple Segments (DIMS) spectacle lenses. Participants who completed the 2-year RCT were followed for a total of 6 years; their cycloplegic refractions and axial length were measured. Group 1 (n = 36) wore DIMS spectacles for 6 years; Group 2 (n = 14) wore DIMS lens for the first 3.5 years and SV spectacles afterwards; Group 3 (n = 22) wore SV spectacles in the first 2 years and switched to DIMS; Group 4 (n = 18) wore SV spectacles in the first 2 years, switched to DIMS for 1.5 years and then SV spectacles again. Group 1 showed no significant differences in myopia progression (− 0.52 ± 0.66 vs. − 0.40 ± 0.72D) and axial elongation (0.32 ± 0.26 vs. 0.28 ± 0.28 mm, both p > 0.05) between the first and the later 3 years. In the last 2.5 years, DIMS lens groups (Groups 1 and 3) had less myopia progression and axial elongation than the single vision groups (Groups 2 and 4). There was no evidence of rebound after stopping the treatment. Post-wear visual functions in all groups were within norms. The results supported that DIMS lenses provided sustained myopia control without adverse effects over the 6-year study period.Trial registration: clinicaltrials.gov; NCT02206217.

Purpose To investigate and compare the degradation of visual acuity (VA) in myopic presbyopes due to lens-induced astigmatism at near and at far distance. Patients and Methods Fourteen corrected myopic presbyopes were recruited. VA (logarithm of the minimum angle of resolution) was measured binocularly for different conditions of lens-induced astigmatism: cylindrical powers of −0.25, −0.50, −0.75, −1.00, −1.50, and −2.00 diopters (and positive spherical power of half the cylindrical power) with two axis orientations (with-the-rule WTR and against-the-rule ATR) were added to their optical correction. Measurements were carried out at far and near distance both in photopic and mesopic conditions, and for high and low contrast (HC/LC) stimuli. The paired Wilcoxon signed-rank statistics test was used to evaluate difference between conditions. Results The measured VA as a function of the lens-induced astigmatism was described by regression lines in all investigated experimental conditions. The angular coefficients (slopes) of these lines represent the VA degradation, ie, the variation in logMAR corresponding to the addition of 1.00 diopters of cylindrical power. In photopic HC conditions, the VA degradation is significantly more pronounced at far distance than at near distance (0.22±0.06 diopters −1 vs 0.15±0.05 diopters −1 , p = 0.0061 in WTR conditions; 0.18±0.06 diopters −1 vs 0.12±0.05 diopters −1 , p = 0.0017 in ATR conditions), although VAs at near and at far with zero cylinder were similar (−0.14±0.10 vs −0.14±0.08, p = 0.824). Conclusion The better tolerance to lens-induced astigmatism blur at near than at far distance in photopic conditions with HC stimuli is tentatively attributed to a possible experience-mediated neural compensation associated to the tendency of the eye toward an inherent astigmatism at near.

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Many things interfere with good binocular vision in nowadays modern

The work was aimed at comparing contrast sensitivity performance in an indoor environment with two filters, which differ only in the presence of a band at 450±20 nm in the transmittance spectrum. Patients and Methods: Thirty-nine subjects participated. The filters were the Standard (ST) and Professional (PRO) Drive lenses (Hoya, Japan), the latter showing the attenuation band at 450 nm. Photopic contrast sensitivity (CS) was measured at different spatial frequencies from 1.5 to 18 cpd through Functional Acuity Contrast Test with both lenses (LogCS ST and LogCS PRO , respectively). The areas under the curves of LogCS ST and LogCS PRO as a function of the spatial frequency were also considered. Results: In the range of the measured values of LogCS ST for the thirty-nine participants, at each spatial frequency and also for the areas, the difference Δ = LogCS PRO-LogCS ST was found to decrease and change sign from positive to negative as a function of LogCS ST , thus allowing to deduce a threshold (LogCS threshold) for LogCS ST corresponding to Δ=0. Significant CS worsening was found with the PRO compared to the ST lens for the subjects showing LogCS ST > LogCS threshold. Vice versa, CS improvement was found when LogCS ST < LogCS threshold. Conclusion: In the choice of a blue-filtering lens, practitioners should take into consideration that the attenuation of light in the range 420-470 nm is expected to produce a CS worsening in subjects showing a relatively high initial CS (higher than a threshold CS). For these subjects, the general reduction of transmitted light intensity prevails on possible advantages. On the contrary, subjects showing a relatively low initial CS are expected to show a CS improvement because the attenuation of light in the range 420-470 nm is expected to reduce intraocular scattering and to mimic the effect as an optical filter of the human macular pigment, advantages which prevail on the reduction of the transmitted light intensity.