Cataract Zonular cataract 2010-12-12T12:00:37Z HP:0007713 Zonular cataracts are defined to be cataracts that affect specific regions of the lens. Zonular cataracts include specific regions of the lens and include nuclear cataracts, which affect the fetal or embryonic lens nucleus and lamellar cataracts. These tend to affect lens fibers that are formed at the same time, resulting in a shell like opacity. Zonular cataracts can also be characterized as dense or pulverulent (dusty appearing), and can be accompanied by arcuate opacities extending into the lens cortex, called cortical riders. UMLS:C1861821 HP:0010920