A dyeing method for functional contact lenses includes the following steps: providing a dry lens body, including hydrogel with 0-90% water content, silicone hydrogel with 0-90% water content, or a combination thereof; preparing an amphoteric polymethyl ether prepolymer, combining the amphoteric polymethyl ether prepolymer with a hydrophilic monomer to form a masking ring material, and attaching the masking ring material to an inner surface of the dry lens body to form a masking ring layer; dropping a colorant onto the inner surface, making the masking ring layer surround the colorant, irradiating the colorant with an ultraviolet light and then heating and fixing the colorant to form a dyed layer on the inner surface; and placing the dry lens body in water to hydrate and removing the masking ring layer to obtain a wet lens body.