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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2022 - 20232
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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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    Eye movements as a predictor of preference for progressive power lenses
    (Journal of Eye Movement Research, 2022) Concepción Grande, Pablo; González Dosal, Amelia; Cleva Millor, José Miguel; Alonso Fernández, José; Gómez Pedrero, José Antonio; Chamorro Gutiérrez, Eva
    Abstract The purpose of this study is to determine if there is any correlation between the characteristics of the user’s eye movements (EMs) and the preference of the user when wearing different Progressive power lenses (PPLs) distributions. An eye-tracker system with a sample rate of 120Hz and temporal resolution of 8.3ms (Tobii-X3-120) was used to register EMs of 38 PPL users when reading in a computer screen with 2 types of PPLs (PPL-soft and PPL-hard). Number of fixations, complete fixation time, fixation duration mean, saccade duration mean, saccade distance mean, and number of regressions were analyzed for 6 different regions of the computer screen. A statistically significant difference was observed between the characteristics of the user’s EMs and the user’s PPL subjective preference (p<0.05*). Subjects that preferred the PPL-hard presented significantly lower complete fixation time, lower fixation duration mean and lower number of regressions than those subjects indicating a preference for the PPL-soft. Results of this study suggest that eye-tracking systems can be used as PPL design recommendation systems according to the user EMs performance.