Posters

Predicting subjective depth-of-field of the accommodating eye with objective methods

Poster Details

First Author: J.Zapata-Diaz UK

Co Author(s):    R. Iskander   N. Lopez-Gil   J. Alfonso   H. Radhakrishnan           

Abstract Details

Purpose:

To evaluate whether objective methods based on retinal image quality analysis have the capability of predicting subjective depth-of-field for different accommodative states in the view that further understanding of the depth-of-field of the human eye could improve multifocal lens design to correct presbyopia.

Setting:

The University of Manchester (The Eye and Vision Sciences Research Group, UK), Wroclaw University of Technology (Biomedical Signal Processing Group, Poland) and University of Murcia (CiViUM, Spain).

Methods:

Retrospective data from seven young subjects (29.7 ± 7.7 years) were used together with an objective method to estimate depth-of-field from aberrations and pupil size measurements. The metric used to calculate image quality was the augmented Visual Strehl Ratio (VSOTFa). Depth-of-field of the eye was estimated by considering image quality values above several relative thresholds (50% and 80% of the maximum image quality) at focus and with several defocus levels. Results were compared to subjective measurements of depth-of-field for the same subjects and for several accommodation levels (0 to 6 D, in 1 D steps).

Results:

No significant correlation was found between results of objective estimation of depth-of-field and subjective measurements, for the relative thresholds used so far (r^2 = 0.003 for the 50% threshold and r^2 = 0.002 for the 80% threshold).

Conclusions:

The objective method was not able to predict subjective measurements of the depth-of-field of the eye. It is likely that neural factors influencing depth-of-field lead to this mismatch between objective and subjective estimates of depth-of-field.

Financial Disclosure:

NONE