Method for determining a progressive lens and associated system

A system for determining a design of a progressive lens intended to be worn by a wearer, the progressive lens comprising a front surface and a back surface disposed closer to an eye of the wearer, the front surface comprising a first progression profile and the back surface comprising a second progression profile, the system comprising:

• measurement circuitry configured to measure changes in a body posture of the wearer by sensing movements of the wearer when seeing a visual pattern moving along a mediolateral direction, where the mediolateral direction is with respect to the wearer and is in contrast to vertical and anteroposterior directions;
• at least one processor configured to:
• obtain first data representative of a first measurement of a first postural instability of the wearer when seeing the visual pattern moving along the mediolateral direction, the first measurement being determined by the measuring changes in the body posture of the wearer when seeing the visual pattern moving along the mediolateral direction, the mediolateral direction corresponding to a horizontal direction in a plane parallel to a frontal plane which is perpendicular to a median plane,
• determine a repartition between the first progression profile and the second progression profile based on said first data, wherein, when said repartition is defined by a progression profile on the back surface versus a complementary progression profile on the front surface, said repartition is an increasing function of said first postural instability, and
• determine surface characteristics of the progressive lens to be manufactured based on the repartition determined between the first progression profile and the second progression profile.

A method for generating a design of a progressive lens intended to be worn by a wearer, the progressive lens including a front surface and a back surface disposed closer to an eye of the wearer, the front surface including a first progression profile and the back surface including a second progression profile, the method comprising:

• measuring changes in a body posture of the wearer by sensing movements of the wearer when seeing a visual pattern moving along a mediolateral direction, where the mediolateral direction is with respect to the wearer and is in contrast to vertical and anteroposterior directions;
• first measuring of a first postural instability of the wearer when seeing the visual pattern moving along the mediolateral direction, the first measuring being determined by the measuring changes in the body posture of the wearer when seeing the visual pattern moving along the mediolateral direction, the mediolateral direction corresponding to a horizontal direction in a plane parallel to a frontal plane, which is perpendicular to a median plane;
• obtaining first data representative of the first measurement of the first postural instability of the wearer when seeing the visual pattern moving along the mediolateral direction;
• determining, by a processor, a repartition between the first progression profile and the second progression profile based on the first data, wherein, when said repartition is defined by a progression profile on the back surface versus a complementary progression profile on the front surface, said repartition is an increasing function of said first postural instability;
• determining, by the processor, surface characteristics of the progressive lens to be manufactured based on the repartition determined between the first progression profile and the second progression profile;
• and
• generating, by the processor, the design of the progressive lens to be manufactured based on the determined surface characteristics.