Process for producing a progressive ophthalmic lens comprising an anterior face, a posterior face and an intermediate medium, the process comprising the following steps: - producing a semi-finished lens in which the anterior face comprises variations in sphere and in cylinder so as to obtain a first contribution to variations in optical power and in astigmatism of the lens during use of said lens by a wearer; - measuring at least one behavioural characteristic of a wearer of the lens; - determining values of a physical quantity of the lens, which physical quantity is distinct from the sphere and from the cylinder of the anterior face, so that a second contribution to the variations in optical power and in astigmatism of the lens results from variations in said physical quantity between different points of the lens, said second contribution realizing a personalization of the variations in optical power and in astigmatism of the lens dependent on the measured behavioural characteristic, and - modulating the physical quantity to obtain said second contribution; in which the physical quantity comprises a sphere and a cylinder of the posterior face of the lens, and said physical quantity is modulated during machining carried out to rework the posterior face of the lens, or the physical quantity comprises a refractive index of a substantially transparent layer comprised in the semi-finished lens, said layer being made of a material the refractive index of which is adjustable by irradiation, and said physical quantity is modulated by selectively irradiating various segments of said layer variably, or said physical quantity comprises a refractive index of the intermediate medium of the lens, said intermediate medium being made of a material the refractive index of which is adjustable by irradiation, and said physical quantity is modulated by selectively irradiating various segments of the intermediate medium variably, the process further comprising the following step: - determining values of another physical quantity at various points of the lens with a view to endowing the lens with a prescription optical power and a prescription astigmatism, in which said other physical quantity comprises a sphere and a cylinder of the posterior face of the lens, and said other physical quantity is modulated during machining carried out to rework the posterior face of the lens, or said other physical quantity comprises a refractive index of a substantially transparent layer comprised in the lens, said layer being made of a material the refractive index of which is adjustable by irradiation, and said other physical quantity is modulated by selectively irradiating various segments of said layer variably, or said other physical quantity comprises a refractive index of the intermediate medium of the lens, said intermediate medium being made of a material the refractive index of which is adjustable by irradiation, and said other physical quantity is modulated by selectively irradiating various segments of the intermediate medium variably, characterized in that the behavioural characteristic comprises an amplitude of horizontal eye movements with respect to a rotation of the head of the wearer, when the wearer scans a field of vision horizontally, and in that said other physical quantity is distinct from the sphere and from the cylinder of the anterior face, and from the physical quantity from which the second contribution to the variations in optical power and in astigmatism of the lens is derived. - producing a semi-finished lens in which the anterior face comprises variations in sphere and in cylinder so as to obtain a first contribution to variations in optical power and in astigmatism of the lens during use of said lens by a wearer; - measuring at least one behavioural characteristic of a wearer of the lens; - determining values of a physical quantity of the lens, which physical quantity is distinct from the sphere and from the cylinder of the anterior face, so that a second contribution to the variations in optical power and in astigmatism of the lens results from variations in said physical quantity between different points of the lens, said second contribution realizing a personalization of the variations in optical power and in astigmatism of the lens dependent on the measured behavioural characteristic, and - modulating the physical quantity to obtain said second contribution; - determining values of another physical quantity at various points of the lens with a view to endowing the lens with a prescription optical power and a prescription astigmatism,