Spectacle Lenses Research Articles

Visual impact of diffusion optic technology lenses for myopia control.

To assess the visual impact of Diffusion Optics Technology™ 0.2 DOT lenses (SightGlass Vision Inc.) designed for myopia control on primary gaze. DOT spectacle lenses contain light scattering elements that scatter light as it passes through the lens which, in turn, reduces retinal image contrast. Fifty-one children (12.2 ± 1.3, range 10-14 years; 51% females) were randomly assigned to wear DOT spectacle (n = 27) or single vision lenses (n = 24) across six investigational sites in North America. Binocular high- and low-contrast distant visual acuities, near visual acuity, reading speed, contrast sensitivity, stereoacuity and glare were assessed in primary gaze after at least 3 years of wear, with the study 95% powered in all metrics to detect significant differences between the groups. Mean binocular distance high-contrast (-0.09 ± 0.02 vs. -0.08 ± 0.02 logMAR, p = 0.81), low-contrast (0.05 ± 0.02 vs. 0.07 ± 0.02 logMAR, p = 0.52) and near visual acuity with glare sources (-0.06 ± 0.03 vs. -0.09 ± 0.03 logMAR, p = 0.32) were similar for DOT and single vision lens wearers, respectively. Contrast sensitivity was similar between children wearing DOT or single vision lenses across 11 of the 16 spatial frequencies (p > 0.05). Mean stereopsis was similar (p = 0.30) with the DOT lenses (33.2 ± 12.5″) and single vision lenses (38.1 ± 14.2″). Functional reading speed metrics were similar in both study groups, as was the objectively measured head tilt during reading (p > 0.05). The mean halo radius was 0.56° ± 0.17° with the DOT lenses compared with 0.50° ± 0.12° with single vision lenses (p = 0.02), but the statistically significant difference was smaller than the non-inferiority bound of 0.4°. Diffusion optics technology lenses provide a clinically equivalent visual experience to a standard single vision lens.

Seeking materials from nature for interrupting eye damage: Ultraviolet to blue light blocking clear cellulose films enabled by curcumin

The harms caused by ultraviolet (UV) and blue light to eyes are attracting momentous concern due to growing exposure to artificial illumination and modern IT devices. Herein, a simple and eco-friendly adsorption approach was employed to integrate curcumin, a natural bioactive compound, into the cellulose substrate for the development of flexible and biodegradable filters capable of blocking harmful light. The curcumin/cellulose films demonstrate excellent UV-screening competence and photostability, with UV-A and UV-B screening ratios ranging from 92.8 % to 100 % and 89.2 % to 100 %, respectively. The films could block >96 % of blue light in the wavelength range of 400–500 nm. Meanwhile, the films maintain high transmittance (85.2–89.4 %) and low haze (2.0–2.7 %). The films can efficiently block blue light emanated from sunlight, light-emitting diodes, lighting systems, computer and mobile phone screens. Encouragingly, the incorporation of curcumin led to a substantial increase in the water contact angle, elevating it from 41.6 to 81.3°. Furthermore, the films exhibit excellent antimicrobial properties, biodegradability, and tensile strength in excess of 72 MPa. Therefore, these films fabricated entirely from natural resources have the potential to achieve practical applications such as food packaging and spectacle lens, especially suitable for electronic screen protectors.

The effect of individualized ocular refraction customized spectacle lenses on myopia control in schoolchildren: A 1-year randomised clinical trial.

The aim of this study was to investigate the effect of individualized ocular refraction customized (IORC) spectacle lenses with different actual amounts of peripheral myopic defocus (MD) on myopia control over 1 year. These lenses compensate for the original peripheral refraction via the free-form surface on the back of the lens. This 1-year, double-masked randomised clinical trial included 184 myopic schoolchildren aged 8-12 years. Participants were randomised to receive IORC lenses with high (IORC-H group, +4.50 D), medium (IORC-M group, +3.50 D) or low (IORC-L group, +2.50 D) MD or single-vision (SV) lenses. The spherical equivalent refractive error (SER) and axial length (AL) were measured at baseline and 6-monthly intervals. After 1 year, the mean (SD) changes in SER were -0.18 (0.37), -0.36 (0.37), -0.52 (0.39) and -0.60 (0.42) D for the IORC-H, IORC-M, IORC-L and SV groups, respectively. Compared with the SV group, the effects of slowing myopia progression were 70%, 40% and 13% for the IORC-H (difference of 0.47 D, p < 0.001), IORC-M (difference of 0.32 D, p = 0.001) and IORC-L (difference of 0.15 D, p > 0.05) groups, respectively. The mean (SD) changes in AL were 0.12 (0.16), 0.23 (0.17), 0.29 (0.17) and 0.36 (0.17) mm for the IORC-H, IORC-M, IORC-L and SV groups, respectively. The axial elongation was 67%, 36% and 19% lower in the IORC-H (difference of 0.25 mm, p < 0.001), IORC-M (difference of 0.15 mm, p < 0.001) and IORC-L (difference of 0.10 mm, p = 0.04) groups, respectively, compared with the SV group. The IORC-H group exhibited significantly less axial elongation than the IORC-M and IORC-L groups (p = 0.01 and p < 0.001, respectively). Compared with the IORC-M and IORC-L lenses, the IORC-H lens was found to have superior efficacy in inhibiting myopic progression and slowing eye growth in schoolchildren, with better myopia control efficacy in younger children.

THE EFFECT OF BLUE LIGHT BLOCKING SPECTACLES LENSES FOR DIGITAL ASTHENOPIA

This systematic review evaluated the impact of blue-blocking (BB) spectacle lenses on digital asthenopia, considering 9 relevant studies published in the last de­cade. While two studies indicated some effectiveness of BB lenses in reducing symptoms like eye pain and heavy eyes, others did not show significant differences compa­red to no-block (NB) lenses in various eye strain symp­toms. Overall, the evidence lacks conclusive support for the effectiveness of BB filters in alleviating digital eye strain (DES) symptoms, emphasizing the need for more standardized and comprehensive research in this area.

Spoilt for choice: intraocular lenses for correction of presbyopia : Classification, optical properties, clinical results

Spoilt for choice: intraocular lenses for correction of presbyopia : Classification, optical properties, clinical results

Spectacle Lenses With Highly Aspherical Lenslets for Slowing Axial Elongation and Refractive Change in Low-Hyperopic Chinese Children: A Randomized Controlled Trial

Purpose: Spectacle lenses with highly aspherical lenslets (HAL) have been shown to effectively retard myopia progression in myopic children. This study aimed to investigate the impact of spectacle lenses with HAL on refractive and axial length (AL) changes in Chinese children with low amount of hyperopia. Design: Randomized controlled trial Methods: A total of 108 Chinese children aged 6.0 to 9.9 years and spherical equivalent refractive error (SERE) from 0.00 to +2.00 D were randomly allocated into two groups: the HAL group and the single vision spectacle lens (SVL) group. Cycloplegic refraction, AL, and uncorrected visual acuity (UCVA) was measured at baseline, three months, six months, and 12 months after lens dispensing. The duration of spectacle lens wear was monitored using a wearable device attached to the spectacle frame and by questionnaire logs provided by participants at each follow up visit. Results: The one-year SERE change was -0.19 [-0.32, 0.03] D and −0.23 [-0.36, 0.05] D in the SVL and HAL groups (P=0.883). The one-year AL elongation was 0.24 [0.18, 0.34] mm and 0.19 [0.12, 0.27] mm in the SVL and HAL groups (P=0.057). In the HAL group, changes in AL and SERE were significantly correlated to lens wearing time (P<0.001 and P=0.024, respectively). Participants in the HAL group who wore their lenses for more than 30 hours per week had significantly slower AL elongation (0.11 [0.05, 0.17] mm) compared to their SVL counterparts (0.27 [0.21, 0.33] mm) (P<0.001). Conclusion: Spectacle lenses with HAL significantly reduced AL elongation in low hyperopic children who wore lenses for over 30 hours per week. A dose-response relationship was evident with longer lens wearing time associated with less AL change.

Contact lenses as a preferred choice for vision correction in various clinical scenarios with regard to work environment

Amendment to the Regulation of Minister of Labour and Social Policy of 1 December 1998 on safety and occupational hygiene at positions equipped with display monitors, adopted on October 18th, 2023, entered the long-awaited by employees possibility of reimbursement for corrective contact lenses, adjusting the Polish legislation to European directive regulating working conditions with display screen equipment. Contact lenses in many cases of refractive errors can be an alternative to prescription glasses method of correcting the visual impairment. There are however many clinical conditions, in which contact lenses can provide a better corrective effect on visual acuity. The information contained in medical databases of articles and scientific journals (PubMed, Biblioteka Nauki), online publications (Lippincott Journals), books, applicable legal regulations (available in Internetowy System Aktów Prawnych) and guidelines published by organizations and associations (Nofer Institute of Occupational Medicine in Łódź, Occupational Safety and Health Administration, Tear Film & Ocular Surface Society) were analyzed, covering the discussed issues over the years 2000-2023. Non-correction or suboptimal correction of a refractive error can cause a wide variety of troublesome symptoms, such as eye pain, headache, double vision, balance disorders, nausea, disturbances in the perception of the surroundings, contributing to poorer work efficiency, faster fatigue or an increased risk of error. This article, which is a narrative review, aims to present these conditions, as well as provide a brief overview of the types of contact lenses used, complications that may result from their use and contraindications to the use of this type of correction. Med Pr Work Health Saf. 2024;75(4):383-390.

Comparative Effect of Cylindrical Lenses Versus Spherical Equivalent on Contrast Sensitivity

Background: Astigmatism is a common refractive error that affects visual acuity and contrast sensitivity. Cylindrical lenses and spherical equivalents are commonly prescribed to correct these errors, but their comparative effects on contrast sensitivity are not well-documented.Objective: To compare the effects of cylindrical lenses versus spherical equivalents on contrast sensitivity in individuals with astigmatism.Methods: A randomized controlled trial was conducted involving 68 participants with astigmatism, aged 15 to 30 years. Participants were randomly assigned to receive either cylindrical lens correction or spherical equivalent correction. Contrast sensitivity was measured using the Pelli-Robson chart at baseline and during two follow-ups over three months. Data were analyzed using Friedman's Two-Way Analysis of Variance and the Wilcoxon Signed Ranks Test, with p ≤ 0.05 considered statistically significant.Results: The mean contrast sensitivity decreased from 1.95 ± 0.07 to 1.93 ± 0.09 over three months. Cylindrical lenses resulted in higher contrast sensitivity scores (2.00 in 67.6% of cases at final visit) compared to spherical equivalents (44.1%, p &lt; 0.001).Conclusion: Cylindrical lenses significantly improve contrast sensitivity compared to spherical equivalents, particularly in moderate to high astigmatism.

Practice patterns in pediatric myopia management: Insights from a 2023 survey among Indian ophthalmologists.

This study investigates the practice patterns related to paediatric myopia among Paediatric Ophthalmologists in India, based on a 2023 survey conducted via Google Forms. The survey aimed to gather insights into physicians' perceptions and experiences concerning the clinical and treatment aspects of myopia in children. The survey reveals several key insights into current practice patterns among Paediatric Ophthalmologists in India regarding paediatric myopia management. The recommended mean age for a child's first eye checkup is 3 years, underscoring the importance of early detection. Refractive error thresholds for prescribing spectacles are set at 3.0 D for infants, 2.0 D for preschool children, and 1.0 D for school-going children older than 3 years. There is a growing trend in using 0.01% Atropine eye drops for myopia management, with a mean prescription age of 4.83 years. Notably, 80.11% of respondents prioritize documenting myopia progression regardless of the child's age. Orthokeratology and Peripheral Defocus spectacle lenses are gaining recognition, and lifestyle modifications such as increasing outdoor activities and reducing near activities are widely acknowledged as effective. While most respondents do not use progressive lenses for myopia, there is significant emphasis on axial length measurements and considering the lag of accommodation. Additionally, under-correction of myopia is favored by a notable proportion of practitioners. These findings indicate a shift towards early intervention and evidence-based strategies in myopia control. The survey highlights a shift towards early intervention and evidence-based myopia control strategies among practitioners. There is, however, room for improvement in standardizing approaches and considering additional factors like axial length and lag of accommodation. Collaborative efforts among policymakers, health regulatory bodies, and industry stakeholders are essential to enhance the accessibility and affordability of myopia control treatments and address the growing health burden associated with paediatric myopia.

Most State Medicaid Programs Cover Routine Eye Exams For Adults, But Coverage Of Other Routine Vision Services Varies.

More than twelve million US adults ages forty and older are affected by vision impairment, and projections suggest that this number will double by 2050. Although most vision impairment can be eliminated with corrective lenses, many adults lack access to routine eye care. In this study, we analyzed detailed state-by-state Medicaid policies for 2022 and documented variability in coverage for adult vision services. Most fee-for-service Medicaid programs covered routine eye exams, although many did not cover glasses (twenty states) or low vision aids (thirty-five states), and about two-thirds of states with routine coverage required enrollee cost sharing. Managed care plans generally provided consistent or enhanced coverage relative to fee-for-service programs, although coverage sometimes varied between plans within a state. We estimated that about 6.5million and 14.6million adult enrollees resided in states without comprehensive coverage for routine eye exams and glasses, respectively. These findings reveal important gaps and opportunities for states to increase access to routine vision care.

Spectral transmission of commercially available high-energy visible light-filtering spectacle lenses.

High-energy visible (HEV) light-filtering spectacle lenses are being widely promoted despite limited evidence to support their use. The spectral transmission properties of commercially available lenses varied, particularly in the HEV light region, and they do not perform in the same way for transmission of ultraviolet (UV)-A and HEV light. Although HEV light is important for several visual and nonvisual functions, there are concerns over the potential adverse effects of increased HEV light exposure. High-energy visible light-filtering spectacle lenses are being widely marketed to promote ocular health and improve sleep by reducing exposure to HEV light. This study reports on the spectral transmission characteristics of commercially available HEV light-filtering spectacle lenses based on the recommendations of the Spectral Bands Task Force technical report. The spectral transmission of light through nine afocal plastic lenses, including eight commercially available HEV light-filtering lenses and one clear uncoated control lens, was evaluated using a Cary 5000 UV-Vis-NIR spectrophotometer (Agilent Technologies, Johannesburg, South Africa) for wavelengths 250 to 780 nm. The percentage transmission values are reported for UV radiation and visible light, with emphasis for HEV light (380 to 500 nm) and the three subbands therein. All lenses blocked UV-C and UV-B radiation (250 to 315 nm). For UV-A radiation (315 to 380 nm), six lenses showed optimal 100% absorption, whereas three lenses allowed ≤12%. The transmission values for the HEV light-filtering lenses ranged from 55 to 90% and 75 to 95% for HEV light of wavelengths 400 to 455 nm and 455 to 500 nm, respectively. In contrast, the control lens showed 92 (400 to 455 nm) and 93% (455 to 500 nm) transmission. The HEV light-filtering spectacle lenses varied in their transmission properties and do not necessarily perform in the same way for transmission of UV-A and HEV light. Optometric personnel should consider these transmission properties, particularly for HEV light, when making recommendations to patients about HEV light-filtering spectacle lenses.

Comparison of near visual performance in myopia control spectacle lenses

Comparison of near visual performance in myopia control spectacle lenses

Comparing reading performance in toric vs. spherical contact lens correction of patients with astigmatism: Preliminary results

Comparing reading performance in toric vs. spherical contact lens correction of patients with astigmatism: Preliminary results

High myopia: Reviews of myopia control strategies and myopia complications.

Myopia and especially high myopia are recognised as major public health concerns. Although the prevalence of high myopia in young children is low, 10-20% of high school children in Asia have high myopia, with many still progressing, and one in three patients with high myopia develop visual impairment with age. Most participants in myopia control studies have low and moderate myopia; relatively little is known about myopia control in high myopia. Literature searches were undertaken in MEDLINE and EMBASE to identify publications in English, investigating (Aim 1) the efficacy of myopia control strategies (environmental, pharmacological and optical) in high myopia (≤-6.00 D) and (Aim 2) the complications of high myopia using keywords. Outcomes included change in spherical equivalent refractive error (SE) and/or axial length (AL) to evaluate progression in high myopia. Aim 1: Twelve studies were identified that reported the efficacy of optical and pharmacological (none on environmental) interventions on AL and SE for high myopia control. A statistically significant reduction in progression of SE and AL in high myopes was reported with 1% and 0.5% atropine. Defocus Incorporated Multiple Segment spectacle lenses had lower efficacy in slowing high myopia progression compared to moderate and low myopia. Ortho-K lenses were equally effective in reducing myopia progression in low, moderate and high myopia. Aim 2: Myopic patients have an increased risk of myopic macular degeneration, retinal detachment, cataract and glaucoma, with the risk increasing with the level of myopia. High myopia has significant effects on quality of life, risk of pathological complications and vision impairment. Young children, excluding those with some syndromic associations, who are fast progressing moderate and high myopes require early intervention and close monitoring. Further research investigating the efficacy of myopia control strategies in highly myopic patients, both independently and through combination treatments, are necessary.

The efficacy and safety of combination therapy of repeated low-level red light and defocus-incorporated multiple segments spectacle lenses for myopia control in children: the study protocol for a 12-month, randomized, parallel-controlled, and single-center clinical trial

BackgroundMyopia is increasing in prevalence worldwide. Combination therapy showed a better effect on myopia control than monotherapy. Repeated low-level red light therapy (RLRL) therapy and defocus-incorporated multiple segment (DIMS) spectacle lenses have been reported to retard myopia progression significantly. However, whether these two therapies are better than one is still unknown. The present study aims to report the study protocol of a trial designed to evaluate the efficacy and safety of combination therapy of RLRL and DIMS versus DIMS alone for reducing the progression of myopia among Chinese school-aged children.MethodsThis study is a 12-month, randomized, parallel-controlled, single-center clinical trial. We will recruit children aged 8–12 years with spherical equivalence (SE) between − 0.50 D and − 6.00 D under cycloplegia in both eyes. We will recruit 66 participants with an allocation ratio of 1:1 from our hospital. Participants in the intervention group will be treated with an RLRL therapy device twice a day from Monday to Friday at home, 3 min per session, with a minimum interval of 4 h, under the supervision of their parents/guardians. They will wear DIMS spectacles for myopia correction during the day. Participants in the control group will not receive the RLRL therapy and will only wear DIMS spectacles to correct myopia. Participants from both groups will attend the hospital every 6 months.The primary outcome is the change in axial length at 12 months. Secondary outcomes include changes in refraction under cycloplegia, optical coherence tomography (OCT), multifocal electroretinogram (mfERG), color vision, and participants’ self-reporting of adverse events at 12 months.DiscussionThis study will report the efficacy and safety outcome of the combination therapy of RLRL and DIMS versus DIMS for school-aged children with myopia in detail.Trial registrationChiCTR2300075398. Registered 4 September 2023. https://www.chictr.org.cn/bin/project/edit?pid=200751.

Age-matched analysis of axial length growth in myopic children wearing defocus incorporated multiple segments spectacle lenses

Background/aimsDefocus incorporated multiple segments (DIMS) spectacle lenses are known to be able to inhibit axial length (AL) growth in myopic children compared with single vision (SV) spectacle lenses. However, it...

Protective properties of spectacle lenses used as ultraviolet blockers

In this study, we evaluated the UV transmittance of spectacle lenses in the Turkish market, which are reported to have UV blocking properties, and tested their suitability. Samples were obtained from patients who were admitted to the ophthalmology outpatient clinic of our hospital for refractive error and who wore glasses as UV block. No limitation was made regarding the spectacle size and duration of spectacle wear. Measurements were tested by the principal investigator using an ultraviolet detector. The right and left lens were measured separately. All measurements were performed at room temperature (22-25°C) in a humidity regulated (20-40%) room without direct light. UV protection level was measured for 120 spectacles used for refractive errors. Only 28 (23.3%) of 120 glasses had protection level up to 400 nm UV. Twenty-four (20%) of the glasses had a protection level of 0 even though they were labeled as having UV blocking properties. It is clear that strict regulations need to be implemented to improve the protection levels of glasses.

High tech for high performance

Optician presents a selection of cutting edge ophthalmic lens products designed to deliver top notch visual performance

Artificial intelligence 6

Eluned Creighton-Sims considers the role of AI in ophthalmic lens design

Describing the Eye Health of Newly Arrived Refugees in Adelaide, South Australia.

This study describes the eye health of newly arrived refugees attending a state-funded health service in Adelaide, South Australia, helping to address the paucity of data on the eye health of refugees. Patients attending the Refugee Health Service undergo comprehensive assessment by an on-site optometrist with accredited interpreters if they have eye symptoms, personal or family history of eye disease, or visual impairment (using World Health Organization definitions). A retrospective audit of this service was performed to obtain patient demographics, presenting best-corrected distance visual acuity (better-seeing eye), diagnoses, and management. In 2017-2018, 494 of the 1400 refugees attending the service underwent an optometry assessment (age range 1-86 years, mean age 33.1 ± 18.6 years, 53% female). Regions of origin included the Middle East (25%), Bhutan (24%), Afghanistan (22%), Myanmar (15%), and Africa (14%). Of the 124 cases of visual impairment, 78% resolved with corrective lenses and 11% were due to cataracts. Ophthalmology follow-up was required for 56 (11%) patients, mostly for cataracts (22 patients). Newly arrived refugees have high rates of visual impairment from refractive error and cataracts. Integration of optometry and state-based refugee health services may improve the timely detection and treatment of these conditions.