High-index ophthalmic lenses are commonly prescribed for individuals with moderate to severe myopia (≥ -6.00 D) due to their ability to reduce lens thickness and weight, enhancing cosmetic appearance and comfort. However, a potential drawback of these lenses is the increased chromatic and higher-order aberrations, which may compromise visual performance and overall wearer satisfaction. This cross-sectional, observational study with prospective elements was conducted to assess the extent of chromatic aberration across various high-index lens materials, categorised based on their Abbe number (V-number), and its impact on visual acuity, optical quality, and subjective satisfaction. The study included spectacle wearers aged 18 to 45 years, categorised by degree of myopia and lens design. Individuals with known nuclear or cortical cataracts and any history of ocular pathology were excluded to avoid confounding effects related to myopia shifts in early senile changes. Lens materials included indices ranging from 1.60 to 1.74, with Abbe values ranging from 32 to 42, and quality control (QC) checks were conducted for lens material properties, anti-reflective coating integrity, and index verification using standard optical bench and spectrophotometry tools. Data were stratified by age group, spherical and cylindrical power, and lens category (aspheric, atoric, etc.). A minimum sample size was calculated based on effect size from pilot data, with drop-out rates monitored over a 12-month follow-up for comfort and visual quality feedback. The study employed both parametric and non-parametric statistical tools, after testing data normality, given the skewed distribution of subjective satisfaction scores and power ranges. The results suggest that higher-index lenses with lower Abbe numbers introduce more chromatic aberration, which may influence wearer comfort and clarity, especially under varying lighting conditions. Our findings underline the importance of balancing refractive correction needs with material selection to ensure optimal optical performance and patient satisfaction in high myopia management.
Author
(s) Details
Parmar G
Retail Supervisor, Specs Savers Opticals & Audiologists, London, UK.
Dalal D
Department of Optometry, Bapubhai Desaibhai Patel Institute of Paramedical
Sciences (BDIPS), India.
Dudhiyawala K
Bapubhai Desaibhai Patel Institute of Paramedical Sciences (BDIPS),
Charotar University of Science & Technology (CHARUSAT), Gujarat, India.
Please see the book here:- https://doi.org/10.9734/bpi/msti/v13/5206
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