Long-chain esters of retinol are prepared via a chemoenzymatic process from short-chain retinyl esters and an appropriate long-chain acid or ester in the presence of an enzyme. The frame includes a hollow body that may be filled with a ballast material, such as an antiseptic medium, to suppress longitudinal vibrations and to reduce hygienic effects of excess. The lens has a front surface that is subdivided into distant vision and near vision portions.