Iridization, also known as iridescence, refers to the appearance of brightly colored rings around a light source. The iridization of the front of the eye is due to the spectrophotometric effect of a change in the refractive power of the eye, which breaks down the white light from the front into multiple color components depending on the wavelength of the light it contains, resulting in a typical colored halo. Iridescence is a common symptom in eye diseases, and can be seen in glaucoma, conjunctivitis, corneal edema, incipient cataracts, and other eye diseases. Treatment of primary eye disease. The patient can be asked to view a light source through a narrow slit that is placed vertically and moved in front of the pupil. In the case of physiologic lens iridopsia, the iris is only partially visible and its position changes with the movement of the slit slice. In pathologic iridopsia, the color ring remains round and only slightly darkened during the movement of the slit.