A viscoelastic preparation for use in methods for the treatment of the bodies of humans or animals, in particular for use as a hydrating and protective substance for the cornea during a surgical method of ophthalmic surgery, in which preparation forms a protective layer on the cornea and guarantees an optical enlargement effect of the visual field observable through the cornea； the preparation comprises a water-based phosphate buffer and, as a weight/volume percentage, at least: - at least one polymer for increasing the viscosity selected from the group comprising hydroxypropyl methylcellulose HPMC, carboxymethylcellulose, hydroxyethylcellulose, hyaluronic acid, sodium alginate, hydroxypropylguar polyvinylpyrrolidone, polyvinyl alcohol, polymethacrylic acid, copolymer with polyoxyethylene-polyoxypropylene and polyethylene glycol in a quantity of between 0.2% and 20%； - xanthan gum in a quantity of between 0.01 % and 1 %； - carrageenan in a quantity of between 0.005% and 0.5%.
