Person:
Alonso Fernández, José

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First Name
José
Last Name
Alonso Fernández
URI
https://hdl.handle.net/20.500.14352/79966
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Óptica
Area
Optica
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2016 - 201912020 - 20232
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Item Type: Publication × Subject: 617.751 ×

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Now showing 1 - 3 of 3
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    Theoretical performance of progressive addition lenses with poorly measured individual parameters
    (Ophthalmic and Physiological Optics, 2023) Pascual, Eduardo; Gómez Pedrero, José Antonio; Alonso Fernández, José
    Purpose: The aim of this paper was to present a theoretical study of how poorly measured individual parameters affect the optical performance of progressive addition lenses (PALs). Modern progressive lenses can be prescribed based on parameters such as vertex distance, pantoscopic and wrap angles. These parameters can be measured from the lens wearer using specific devices; however, not all of them can be measured with the same precision, and the impact of measurement errors on the lens performance is still unknown. Methods: Data from 1900 patients were used to simulate the performance of four PAL designs with different degrees of complexity: perfect individual design, individual design with induced errors in the individual parameters, optimised design and conventional/basic design. For each patient and design, a quality metric was calculated to describe the optical performance of the lens. Results: The design having the best performance was the perfect individual design, followed by the individual design with induced errors, the optimised design and finally the conventional/basic design. Conclusions: Individual designs with measurement errors have better optical performance than lenses with less complexity, such as the optimised or conventional designs. This knowledge is useful for the eye care professional to make informed choices when dispensing these lenses.
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    Phenomenological model of visual acuity
    (Journal of Biomedical Optics, 2016) Gómez Pedrero, José Antonio; Alonso Fernández, José
    We propose in this work a model for describing visual acuity (VV) as a function of defocus and pupil diameter. Although the model is mainly based on geometrical optics, it also incorporates nongeometrical effects phenomenologically. Compared to similar visual acuity models, the proposed one considers the effect of astigmatism and the variability of best corrected VV among individuals; it also takes into account the accommodation and the “tolerance to defocus,” the latter through a phenomenological parameter. We have fitted the model to the VV data provided in the works of Holladay et al. and Peters, showing the ability of this model to accurately describe the variation of VV against blur and pupil diameter. We have also performed a comparison between the proposed model and others previously published in the literature. The model is mainly intended for use in the design of ophthalmic compensations, but it can also be useful in other fields such as visual ergonomics, design of visual tests, and optical instrumentation.
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    Evaluation of an Eye-Tracking-Based Method for Assessing the Visual Performance with Progressive Lens Designs
    (Applied Sciences, 2023) Concepción Grande, Pablo; Chamorro Gutiérrez, Eva; Cleva Millor, José Miguel; Alonso Fernández, José; Gómez Pedrero, José Antonio
    Due to the lack of sensitivity of visual acuity (VA) measurement to quantify differences in visual performance between progressive power lenses (PPLs), in this study, we propose and evaluate an eye-tracking-based method to assess visual performance when wearing PPLs. A wearable eye-tracker system (Tobii-Pro Glasses 3) recorded the pupil position of 27 PPL users at near and distance vision during a VA test while wearing three PPL designs: a PPL for general use (PPL-Balance), a PPL optimized for near vision (PPL-Near), and a PPL optimized for distance vision (PPL-Distance). The participants were asked to recognize eye charts at both near and distance vision using centered and oblique gaze directions with each PPL design. The results showed no statistically significant differences between PPLs for VA. However, significant differences in eye-tracking parameters were observed between PPLs. Furthermore, PPL-Distance had a lower test duration, complete fixation time, and number of fixations at distance evaluation. PPL-Near has a lower test duration, complete fixation time, and number of fixations for near vision. In conclusion, the quality of vision with PPLs can be better characterized by incorporating eye movement parameters than the traditional evaluation method.