George D Kymionis,1,2 Konstantinos I Tsoulnaras11Vardinoyiannion Eye Institute of Crete, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece; 2Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, FL, USAWe have read with interest the recently published comparative study regarding the accelerated versus conventional corneal collagen cross-linking (CXL) in the treatment of mild keratoconus. We would like to underline the importance of the CXL treatment time reduction in this time consuming operation.1 Accelerated CXL became popular due to patient and doctor comfort in comparison to the previously widespread use of Dresden protocol which is successful in terms of safety and efficacy. Based on the Bunsen-Roscoe law of reciprocity many modifications to the time and irradiation settings have been proposed while the total energy dose delivered to the cornea should be maintained at 5.4 J/cm2.2View original paper by Sherif