Radiation curable composition for preparing a hybrid sol-gel layer on a surface of a substrate, wherein said composition comprises: a) at least one radiation curable (i.e. polymerizable and/or crosslinkable) material capable of being polymerized and/or crosslinked by a radical polymerization reaction upon exposure to a radiation, said radiation curable material comprising at least two radically polymerizable functional groups; b) at least one organofunctional silane of formula: R (4-m) -Si-(OR') m in which: - m is a number between 1 and 3, preferably m is 3; - OR' is an hydrolysable group; and - R is a hydrocarbyl group optionally containing at least one heteroatom, selected from among oxygen, and nitrogen atoms; c) at least one organofunctional silane of formula: R 1 (4-m) -Si-(OR') m in which: - m is a number between 1 and 3, preferably m is 3; - OR' is an hydrolysable group; and - R 1 is a hydrocarbyl group optionally containing at least one heteroatom, selected from among oxygen, and nitrogen atoms; R 1 comprises at least one radically polymerizable functional group capable of polymerizing with one of the radically polymerizable functional group of the radiation-curable material; and preferably R 1 comprises one radically polymerizable functional group capable of polymerizing with one of the radically polymerizable functional group of the radiation-curable material; d) at least one cationic photoinitiator; preferably, the cationic photoinitiator is combined with a sensitizer; and e) at least one radical photoinitiator. a) at least one radiation curable (i.e. polymerizable and/or crosslinkable) material capable of being polymerized and/or crosslinked by a radical polymerization reaction upon exposure to a radiation, said radiation curable material comprising at least two radically polymerizable functional groups; b) at least one organofunctional silane of formula: R (4-m) -Si-(OR') m in which: - m is a number between 1 and 3, preferably m is 3; - OR' is an hydrolysable group; and - R is a hydrocarbyl group optionally containing at least one heteroatom, selected from among oxygen, and nitrogen atoms; - m is a number between 1 and 3, preferably m is 3; - OR' is an hydrolysable group; and - R is a hydrocarbyl group optionally containing at least one heteroatom, selected from among oxygen, and nitrogen atoms; c) at least one organofunctional silane of formula: R 1 (4-m) -Si-(OR') m in which: - m is a number between 1 and 3, preferably m is 3; - OR' is an hydrolysable group; and - R 1 is a hydrocarbyl group optionally containing at least one heteroatom, selected from among oxygen, and nitrogen atoms; R 1 comprises at least one radically polymerizable functional group capable of polymerizing with one of the radically polymerizable functional group of the radiation-curable material; and preferably R 1 comprises one radically polymerizable functional group capable of polymerizing with one of the radically polymerizable functional group of the radiation-curable material; - m is a number between 1 and 3, preferably m is 3; - OR' is an hydrolysable group; and - R 1 is a hydrocarbyl group optionally containing at least one heteroatom, selected from among oxygen, and nitrogen atoms; R 1 comprises at least one radically polymerizable functional group capable of polymerizing with one of the radically polymerizable functional group of the radiation-curable material; and preferably R 1 comprises one radically polymerizable functional group capable of polymerizing with one of the radically polymerizable functional group of the radiation-curable material; d) at least one cationic photoinitiator; preferably, the cationic photoinitiator is combined with a sensitizer; and e) at least one radical photoinitiator.