A method for determining a progressive ophthalmic lens for a given user for whom a near vision power addition has been prescribed includes the following steps: measuring the user's downward and the vertical horopter on a near-vision target point; measuring the user's near-vision head elevation and/or eye elevation; determining a coefficient of the user's near-vision vertical head participation (Ptvvp); determining a user-specific progressive length (LP) defined by the relationship LP=H (1−Ptvyp), the progressive length being defined as the downward look angle between the mounting cross and the meridian point for which the power achieves the power addition; determining the lens by optimizing in optical computation in worn conditions, using as target a power variation along the meridian with a progressive length equal to said user-specific progressive length.