We present a self-regulating aperture-scalable artificial soft iris, mimicking a real human iris, which can adjust the light transmission by closing and opening in response to external light without any mechanical deformation and circuitry to help protect human eye functioning. The aperture size dynamic control in response to external light is realized by NIR-assisted radially thermal gradient distribution for radially varying hydrogel network density incorporated with light-responsive photochromic dye. The proposed self-regulating artificial iris shows stable performance in a dry and wet environment with fast switching of photochromic ring-opening and closing in on-off light actuation supported by the hydrogel matrix. The proposed scalable, self-regulating, and UV-blocking ability of artificial iris helps protect the eye from malfunctioning as well as replacing damaged iris to restore its function and as a cosmetic purpose.