Bader described iris neovascularization in 1868, and many authors have since reported iris neovascularization associated with patients with diabetes, central retinal vein occlusion, etc. Due to the advancement of examination technology, especially the clinical application of fluorescein angiography, the discovery of iris neovascularization has continued to increase. Iris neovascularization is not a primary disease of the iris, but is secondary to many eye diseases and certain systemic diseases. Because it can develop into or be combined with the formation of fibrovascular membranes, resulting in iridocorneal angle closure and severe neovascular glaucoma, intraocular pressure is often difficult to control, eventually leading to blindness in the affected eye, or even removal of the eyeball due to severe eye pain. Therefore, it is very important to detect and treat it as soon as possible.