A method for the manufacturing of an optical element having a refractive index above 1.59, said method comprising: - a step of providing a predetermined build support , - at least one step A of providing a predetermined volume of a liquid mixture of polymerizable compounds on said support, characterized in that - the liquid mixture of polymerizable compounds comprises: i) at least one compound C1 having at least one alkynyl functional group or at least two functional groups independently selected from the group consisting of alkenyl, isocyanato, episulfide and epoxy functional groups, ii) at least one compound C2 having at least two terminal functional groups independently selected from the group consisting of mercapto and episulfide groups, with the condition that at least one of C1 and C2 is different from a diepisulfide compound, and iii) optionally at least one polymerization initiator, and wherein said method further comprises: - at least one step B of additively manufacturing said optical element by depositing a plurality of predetermined volume elements of said liquid mixture of polymerizable compounds on said predetermined build support, - at least one step C of inducing partial polymerization of the polymerizable compounds in said volume elements at least until the gel point of said liquid mixture of said polymerizable compounds is reached, - a final step D of completing polymerization of the polymerizable compounds in said volume elements to form said optical element. - a step of providing a predetermined build support , - at least one step A of providing a predetermined volume of a liquid mixture of polymerizable compounds on said support, characterized in that - the liquid mixture of polymerizable compounds comprises: i) at least one compound C1 having at least one alkynyl functional group or at least two functional groups independently selected from the group consisting of alkenyl, isocyanato, episulfide and epoxy functional groups, ii) at least one compound C2 having at least two terminal functional groups independently selected from the group consisting of mercapto and episulfide groups, with the condition that at least one of C1 and C2 is different from a diepisulfide compound, and iii) optionally at least one polymerization initiator, i) at least one compound C1 having at least one alkynyl functional group or at least two functional groups independently selected from the group consisting of alkenyl, isocyanato, episulfide and epoxy functional groups, ii) at least one compound C2 having at least two terminal functional groups independently selected from the group consisting of mercapto and episulfide groups, with the condition that at least one of C1 and C2 is different from a diepisulfide compound, and iii) optionally at least one polymerization initiator, - at least one step B of additively manufacturing said optical element by depositing a plurality of predetermined volume elements of said liquid mixture of polymerizable compounds on said predetermined build support, - at least one step C of inducing partial polymerization of the polymerizable compounds in said volume elements at least until the gel point of said liquid mixture of said polymerizable compounds is reached, - a final step D of completing polymerization of the polymerizable compounds in said volume elements to form said optical element. <EOS>