Cover legend: This image shows dye-filled, genetically identified retinal ganglion cells (RGCs). Some RGC types are more likely than others to degenerate in the early stages of glaucoma, one of the leading causes of blindness. RGCs whose dendrites reside in the “Off” sublayer of the inner retina are particular vulnerable. For more information, see the article by El-Danaf and Huberman (pages 2329–2343).