About the Authors

Pablo Artal

pablo@um.es

Affiliation Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain

Antonio Benito

Affiliation Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain

Guillermo M. Pérez

Affiliation Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain

Encarna Alcón

Affiliation Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain

Álvaro De Casas

Affiliation Hospital Universitario Virgen de la Arrixaca, Murcia, Spain

Jaume Pujol

Affiliation Centre de Desenvolupament de Sensors, Instrumentació i Sistemes (CD6), Universidad Politécnica de Cataluña, Tarrasa, Barcelona, Spain

José M. Marín

Affiliation Hospital Universitario Virgen de la Arrixaca, Murcia, Spain

Competing Interests

Co-authors Artal, Benito, Perez and Pujol hold a patent application on the reported approach (United States Patent Application 20100195876; Artal Pablo et al. August 5, 2010). Co-authors Artal and Pujol are minority investors in Visiometrics SL, the manufacturer of the OQAS instrument. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: PA. Performed the experiments: AB GP EA ADC. Analyzed the data: PA AB GP EA ADC JP JMM. Contributed reagents/materials/analysis tools: JP JMM. Wrote the paper: PA.