<p>The invention relates to a method for determining an ophthalmic lens by optimisation, that comprises the steps of: defining a starting surface for a side of the lens having a central area (15) with a diameter D<SUB>ini</SUB> and a peripheral area (17) with a diameter D<SUB>rac</SUB>; selecting an interpolation formula; optimising the lens by applying the interpolation formula to the central (15) and peripheral (17) areas in order to define an interpolated surface having a seam area (16), the interpolated surface minimising a merit function (FM) for different relative altitudes of the peripheral area (17) relative to the central area (15). The invention reduces the thickness of the lens without increasing the obliquity defects for a good visual comfort of the wearer.</p>
