A method for determining a design of a progressive lens intended to be worn by a future wearer, the progressive lens comprising a front surface and a back surface, at least one of the front surface and the back surface comprising a progression profile on its general spherical shape, said at least one progression profile defining a meridian line extending from a distance-vision point to a near-vision point, said meridian line comprising a vertical portion passing through the distance-vision point and an inclined portion passing through the near-vision point, the vertical portion and the inclined portion forming an angle between them, the method including obtaining first data representative of a first measurement of a first postural instability of the future wearer when seeing a visual pattern moving along an mediolateral direction, and determining a reparation between the first progression profile and the second progression profile based on the first data.