A method for adjusting a light adjustable lens in an optical system includes providing a light adjustable lens in an optical system; providing an ultraviolet light source to generate an ultraviolet light; and irradiating the generated ultraviolet light with a light delivery system onto the light adjustable lens with a center wavelength and with a spatial irradiance profile to change a dioptric power of the light adjustable lens by changing a refraction of the light adjustable lens in a refraction-change zone, thereby causing a wavefront sag, defined as half of a product of the change of the dioptric power and the square of a radius of the refraction-change zone, to be within 10% of its maximum over an ultraviolet spectrum.