Toric SCLs improved intermediate visual acuity and Chinese reading performance relative to spherical equivalent correction in young adults with low-to-moderate astigmatism, and support the functional benefit of full astigmatic correction for visually demanding mid-range reading tasks.
Abstract
To evaluate the impact of toric versus spherical equivalent contact lenses on visual acuity and eye-movement-based reading performance in young adults with low-to-moderate astigmatism, using Chinese reading passages to reflect real-world tasks. A participant-masked, randomised, two-period crossover study was conducted in 28 young adults (aged 18–35 years) with low-to-moderate refractive astigmatism (−0.75 to −2.00 dioptre cylinder [DC]). Participants wore toric and spherical equivalent daily disposable soft contact lenses (SCLs) for 1 week each, in random order. Binocular distance, intermediate and near visual acuity were measured and reading performance was assessed during silent reading of standardised Chinese passages using the EyeLink 1000 Plus. Key metrics included reading speed, fixation count, fixation per minute (fpm), fixation per word (fpw), saccade characteristics and regressions. Toric lenses significantly improved binocular intermediate visual acuity at 66 cm (−0.11 ± 0.07 vs. −0.07 ± 0.08 logMAR, p = 0.04) and reading speed (345.37 ± 122.41 vs. 322.49 ± 130.65 characters per minute [cpm], p = 0.03), compared with spherical equivalent lenses. Additionally, toric correction was associated with more efficient eye-movement behaviour, including fewer fixations per word, fewer total fixations, fewer total saccades and fewer regressions (all p < 0.05). Toric SCLs improved intermediate visual acuity and Chinese reading performance relative to spherical equivalent correction in young adults with low-to-moderate astigmatism. These findings support the functional benefit of full astigmatic correction for visually demanding mid-range reading tasks.
In this cross-sectional observational analysis, children wearing HAL spectacle lenses showed higher adjusted odds of measurable dynamic and gross stereopsis than those wearing single-vision lenses, while fine stereopsis remained comparable.
Zhuotong Wu, Yuhao Ye, Yong Ma et al.· Clinical Ophthalmology· 0 citations
It is suggested that when low myopic astigmatism is corrected using spherical-equivalent soft contact lenses, certain binocular vision parameters may demonstrate acute changes and careful binocular vision assessment may therefore be beneficial when prescribing simplified spherical correction in astigmatic patients.
Arjun Sapkota, Nabin Baral· Annals of Medicine & Sur...· 0 citations
PURPOSE
Prolonged digital device use can result in digital eye strain which may be exacerbated by uncorrected astigmatism. This study explored how sustained smartphone reading impacts on visual function and symptoms when astigmatism is corrected with disposable soft toric contact lenses.
METHODS
30 adult contact lens wearers (mean age 23 ± 4 years, mean astigmatism 1.12 ± 0.35 D) habitually using digital devices for ≥10 h/day were fitted with Delefilcon A daily disposable toric contact lenses for 14-days. High and low contrast near visual acuity (VA) were assessed before and after a prolonged smartphone reading task on day 1 and day 14 of lens wear. The severity of digital eye strain symptoms were reported using a 0-100 visual analogue scale following the reading task. Contact lens dry eye symptoms were assessed using the 8-item Contact Lens Dry Eye Questionnaire (CLDEQ-8).
RESULTS
At baseline, the mean high and low contrast near VAs were - 0.08 ± 0.05 and + 0.04 ± 0.08 logMAR, respectively, which did not decline significantly following the prolonged reading task, or after 14 days of lens wear. The average reading speed was not significantly different between day 1 and day 14 of lens wear (251 ± 85 words-per-minute vs 252 ± 80 words-per-minute, p = 0.47). Digital eyestrain symptoms following the reading task (mean of all symptom scores: 13 ± 21) remained stable over the 14-days of lens wear (all p > 0.05), and > 75% of the reported symptoms were ranked as <15/100 in severity. The mean CLDEQ-8 score was 15.2 ± 8.8.
CONCLUSION
The correction of astigmatism with disposable toric contact lenses provided stable functional visual performance, with minimal digital eye strain during a prolonged smartphone reading task. However, over half of participants, reported significant dryness/discomfort (CLDEQ-8, ≥12) during 2-weeks of wear, highlighting a disconnect between short-term digital task symptoms and overall daily lens comfort in participants habitually using digital devices for ≥10 h/day.
Scott A. Read, Luisa H Colorado, Stephen J. Vincent et al.· Contact lens & anterior eye...· 0 citations
The action of ocular ciliary muscle contributes to the accommodation system, especially when the eye focuses on near objects. Sustaining clear near vision during reading requires precise accommodative control. Each change in viewing distance or target detail initially presents a blur stimulus, prompting the accommodation system to adjust lens power to restore retinal image clarity. This dynamic process is continually challenged by variable task demands, including changes in print size. This study compared the accommodation response with different font sizes before and after a near task with a digital device under photopic bright room illumination. Thirty young adults with a mean age of 22.13 ± 1.31 years completed 10 minutes of uninterrupted reading on an iPhone 11 at a fixed near viewing distance. The reading material consisted of black text on a white background with different font sizes of Arial letter equivalent to N5, N8, N10, and N12 under normal photopic room lighting. The dioptric value of accommodation response was measured objectively using an open field Grand Seiko WAM-5500 autorefractor, before and after the reading task. The accommodation response in baseline measurement before reading was 4.20 ± 0.63 D, after reading with N5 size was 4.13 ± 0.63 D, after reading with N8 size was 4.32 ± 0.34 D, after reading with N10 size was 4.39 ± 0.75 D, and after reading with N12 size was 4.55 ± 0.60 D. There was a statistically significant difference in accommodation response before and after reading task only for N12 font size (Wilcoxon signed-rank test: Z = -2.40, p = 0.02). It could be concluded that the action of the ocular ciliary muscle is well controlled for intense small-sized near targets. These findings indicated that the young adult eye responds similarly to small letter sizes after a short duration of reading under photopic room illumination.
A. Ahmad, S. Rosli, Ahmad Syahhir Syah Mohd Zaini· Malaysian Journal of Science...· 0 citations
This study aimed to characterize the changes in choroidal thickness (ChT) in response to optical approaches using the distant-image screen (DIS) device and defocus-incorporated multiple segments (DIMS) lenses.
This is a prospective, randomized, controlled, crossover trial.
A total of 40 children (8–13 years of age) with spherical equivalent refraction (SER) ranging from −0.50 to −6.00 diopters (D) were recruited and randomized into 4 groups: children who watched videos using either a DIS or a tablet computer (TC) and those wearing DIMS or single-vision lenses (SVL).
In their assigned groups, children watched videos for 90 min in stage I, followed by a 3–7-day recovery period. After this recovery period, the children in the TC group were crossed over to the DIS group, and those in the DIS group were crossed over to the TC group for an additional 90 min in stage II. The SER was measured before and after watching videos using an open-field autorefractor. The ChT in the central (1 × 1 mm), superior, inferior, nasal, and temporal regions in 1–3 mm (S3, I3, N3, and T3) and 3–6 mm (S6, I6, N6, and T6) were measured before and after watching videos using full-range swept-source optical coherence tomography (SS-OCT).
The main outcome measure was the changes in regional ChT.
After 90 min of video watching, the SER in the TC group significantly increased after viewing 90-min videos (−2.14 ± 1.15 D vs.-2.26 ± 1.16 D,
p
= 0.036), whereas no significant difference was observed in the DIS group. Among the participants wearing SVL, the ChT changes in the DIS group were significantly higher than those in the TC group at I3 (
p
= 0.036) and T3 (
p
= 0.032), and the changes in other regions were not significantly different between the two groups. For participants using TC, the DIMS group showed greater ChT thickening at C (9.54 ± 3.19 μm,
p
= 0.005), I3 (6.44 ± 3.04 μm,
p
= 0.043), N3 (9.10 ± 3.17 μm,
p
= 0.007), and T3 (8.00 ± 3.17 μm,
p
= 0.017) than the SVL group. The combination of DIMS and DIS exhibited greater ChT thickening at I3 (11.23 ± 4.07 μm,
p
= 0.009) compared to the SVL and TC groups.
Short-term long-distance working mode and myopic defocus may exert beneficial effects on choroidal variation in myopic children.
https://www.chictr.org.cn/showproj.html?proj=184978
, Identifier ChiCTR2200065741.
Unknown authors· Frontiers in Public Health· 0 citations
To evaluate reading performance following an 8-week self-guided eye-movement training programme in people with central vision loss. Thirty-three adults with a retinal disease affecting the central retina, a documented central scotoma and best-corrected visual acuity between 6/21 and 6/120 in the better-seeing eye were enroled. Of these, 25 participants completed a self-guided eye-movement training programme in a clinical setting, for 2 h per week over 8 weeks. To assess the feasibility of remote delivery, eight participants engaged with the same training platform at home. The primary outcome was maximum reading speed, measured binocularly using Minnesota Low Vision Reading (MNREAD) acuity charts. Visual acuity, depression, adaptation to vision loss and self-reported visual function measures were collected at baseline and following the training period. Reading speed increased significantly from baseline following training, by an average of 23 + 24.6 words per minute (wpm), representing a 55% gain. Median reading speed increased by an average of 22.6 wpm for the in-clinic group (n = 25) and 24.3 wpm for the home-based group (n = 8). These findings suggest that self-guided training can enhance reading performance effectively and may be suitable for implementation in both clinical and remote settings. The self-guided eye movement training programme offers an effective and accessible approach to improve reading performance in individuals with central vision loss. This approach has the potential to complement standard care while broadening access to vision rehabilitation services across both clinical and remote settings. NCT01853930 (5-10-2013)
Patricia Grant, Janet P Szlyk, Meesa Royster et al.· Ophthalmic & physiological o...· 0 citations
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