A biomedical device, such as a contact lens, has a surface linked to a polymer comprising boronic acid moieties. The boronic acid monomeric units may be derived from an ethylenically unsaturated monomer containing a boronic acid moiety, such as a vinylphenyl boronic acid or a (meth)acrylamido phenyl boronic acid. The boronic acid moieties may be complexed with mucin, especially epithelial mucin.