Abstract: Methods of facilitating surgical operations that involve the eye or eye area comprise introducing an opthalmologically acceptable composition containing hyaluronic acid into the site of the surgical operation. The hyaluronic acid comprises a chemically unmodified sterilized hyaluronic acid substance having a weight average molecular weight of from 4,500,000 to 12,000,000 daltons, a zero shear viscosity of from 1,000 to 80,000 Pas as measured on a 1.3-1.6% (wv) solution of hyaluronic acid substance in physiological phosphate buffer, and an absorbance at 257 nm of less than 3.5 when measured on a 1% solution of hyaluronic acid substance in sodium chloride buffer in a 10 mm cuvette. Preferred sterilized solutions of hyaluronic acid comprise hyaluronic acid which is chemically unmodified from the naturally occurring hyaluronic acid and has a weight average molecular weight of from 4,500,000 to 8,000,000 daltons, a zero shear viscosity of from 1,000 to 20,000 Pas and an absorbance at 257 nm of less than 3.5.