A method implemented by computer means for determining at least one optical parameter of a lens of eyewear adapted for a person, the method comprising: —an image reception step, during which at least a first image and a second image are received, the first image comprising a front view of the face of the person with at least one part of an eye of the person being directly visible, and the second image comprising a front view of the face of the person with said part of the eye of the person being visible through at least part of the lens, and —an optical parameter determination step, during which at least one optical parameter of the lens is determined based on a comparison between said part on the first and the second image.