18 May 2026
Palazzo del Bo, Padova
Europe/Rome timezone

Sloan letters and Gabor patches for the measurement of the contrast sensitivity function

18 May 2026, 10:05
20m
Archivio Antico (Palazzo del Bo, Padova)

Archivio Antico

Palazzo del Bo, Padova

Via VIII Febbraio, 2, 35122 Padova PD

Speaker

Prof. Marco Barbieri (Università Roma Tre)

Description

Progress in computer-assisted assessment of visual capabilities is enabling the expansion of the number and the scope of visual tests used in routine examinations. Among those, the contrast sensitivity function (CSF) stands out for its relevance to everyday activities and for its potential role as an early flag for degenerative conditions. It is correlated to patient satisfaction after corrections.

In this contribution we will discuss our work on building a collection of solid normative data for the CSF adopting both Gabor patches and Sloan letters using the same LCD-based device commonly employed in optometric practice. While the former may bear significance for refined purposes, due to its narrow spectrum, letters are more relevant for the clinical practice, in the light of their availability and familiarity to the patients. Additionally, we evaluated the reliability of letter-based CSF testing and established normative values in a young healthy population.

Our comparison has highlighted differences in the observations of the response of emmetropised healthy patients to different stimuli under similar conditions. Results showed a tendency of grating-based CSF measurements to display higher values when compared to letter-based ones. Still, letter-based CSF demonstrated reliability and repeatability, allowing to establish solid reference values.

Our findings suggest that normative data should be interpreted with caution by practitioners, and that research and clinical procedures need better alignment.

Authors

Dr Assunta Di Vizio (Università Roma Tre) Prof. Marco Barbieri (Università Roma Tre) Prof. Silvia Tavazzi (Università Milano Bicocca) Prof. Fabrizio Zeri (Università Milano Bicocca)

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