A jig and a cooling fluid injection tool are provided for use in the correction of corneal shape of an eyeball. Correction of the eyeball takes place while the cornea is warmed. The jig includes a shape retention part of a sucking disc configuration having an inner surface side that contacts the eyeball and a grip part formed on an outer surface side of the shape retention part. An inner surface-sided cornea contacting section of the shape retention part is flattened and a cooling fluid injection hole passing through the grip part is formed in the center of the shape retention part with a diameter large enough for a wearer to see outside.