Fuchs endothelial dystrophy (FED) is a progressive eye disorder impacting the cornea, primarily affecting endothelial cells that maintain corneal clarity. Symptoms include blurry vision, halos around lights, increased light sensitivity, discomfort, and declining vision, typically appearing after age 50 and progressing more rapidly in women. Diagnosis involves eye examinations and imaging, with treatments including corneal transplants that can restore function and improve vision.