Central retinal vein occlusion (CRVO) affects one to four percent of Americans older than 40 and very often causes severe vision loss, including "legal blindness" (20/200 vision). While current treatments reduce CRVO symptoms such as macular edema-swelling of the center of the eye's light-sensitive retina-none address the underlying problem, the blocked retinal vein. Researchers recently took direct aim at the problem, using lasers to create a "bypass" around the constricted retinal vein with the aim of restoring near-normal blood flow to the retina.