A method implemented by computer means for optimizing the position of an optical lens to be manufactured in a lens blank, the optical lens being manufactured by machining at least two surfaces of the lens blank, with - the lens blank comprising a first blank surface and a second blank surface linked by a peripheral blank surface and having an axis of symmetry, - the optical lens comprising: a first optical surface obtained by machining the first blank surface while having the lens blank blocked on the second blank surface, said first optical surface being bounded by a first closed contour, a second optical surface obtained by machining the second blank surface while having the lens blank blocked in the first optical surface, said second optical surface being bounded by a second closed contour, and an optical axis intercepting said first and second surface, the method comprising: - a lens blank data providing step during which lens blank data relating to the first, second and peripheral blank surfaces are provided, - an optical lens data providing step during which optical lens data relating to the first, second and peripheral optical surfaces are provided, - a positioning step during which the optical lens is virtually positioned in the lens blank in a position so that at least one of the first optical surface or the second optical surface is included within said lens blank, - an evaluation step during which a manufacturing prism cost function is evaluated, the machining prism cost function corresponding to a weighed sum of the first manufacturing prism to be used when blocking the lens blank on the second surface to machine the first optical surface and of the second manufacturing prism to be used when blocking the lens blank on the first optical surface to machine the second optical surface, wherein the positioning step and the evaluation step are repeated so as to minimize the manufacturing prism cost function. - the lens blank comprising a first blank surface and a second blank surface linked by a peripheral blank surface and having an axis of symmetry, - the optical lens comprising: a first optical surface obtained by machining the first blank surface while having the lens blank blocked on the second blank surface, said first optical surface being bounded by a first closed contour, a second optical surface obtained by machining the second blank surface while having the lens blank blocked in the first optical surface, said second optical surface being bounded by a second closed contour, and an optical axis intercepting said first and second surface, the method comprising: - a lens blank data providing step during which lens blank data relating to the first, second and peripheral blank surfaces are provided, - an optical lens data providing step during which optical lens data relating to the first, second and peripheral optical surfaces are provided, - a positioning step during which the optical lens is virtually positioned in the lens blank in a position so that at least one of the first optical surface or the second optical surface is included within said lens blank, - an evaluation step during which a manufacturing prism cost function is evaluated, the machining prism cost function corresponding to a weighed sum of the first manufacturing prism to be used when blocking the lens blank on the second surface to machine the first optical surface and of the second manufacturing prism to be used when blocking the lens blank on the first optical surface to machine the second optical surface, wherein the positioning step and the evaluation step are repeated so as to minimize the manufacturing prism cost function. a first optical surface obtained by machining the first blank surface while having the lens blank blocked on the second blank surface, said first optical surface being bounded by a first closed contour, a second optical surface obtained by machining the second blank surface while having the lens blank blocked in the first optical surface, said second optical surface being bounded by a second closed contour, and an optical axis intercepting said first and second surface, - a lens blank data providing step during which lens blank data relating to the first, second and peripheral blank surfaces are provided, - an optical lens data providing step during which optical lens data relating to the first, second and peripheral optical surfaces are provided, - a positioning step during which the optical lens is virtually positioned in the lens blank in a position so that at least one of the first optical surface or the second optical surface is included within said lens blank, - an evaluation step during which a manufacturing prism cost function is evaluated, the machining prism cost function corresponding to a weighed sum of the first manufacturing prism to be used when blocking the lens blank on the second surface to machine the first optical surface and of the second manufacturing prism to be used when blocking the lens blank on the first optical surface to machine the second optical surface,