An Etymological Dictionary of the German Language/Star
Star, m., ‘starling,’ from the equiv. MidHG. star, m., OHG. stara, f.; corresponding to AS. stœr, stearn, E. stare, OIc. stare, starre, ‘starling’; primit. allied to Lat. sturnus. E. starling indicates the derivation of ModHG. Sperling (OHG. sparo). — Star, m., ‘cataract’ (of the eye), has been deduced in ModHG. from MidHG. starblint (d) OHG. starablint (comp. Du. staarblind), adj., ‘blind from a cataract,’ which has no connection with the name of the bird, since it more probably belongs to the same root as ModHG. starren (OHG. starên), ‘to look fixedly, stare.’ In AS., besides stœrblind, a curious form, pûrblind occurs, the first component of which is AS. pûr, ‘bittern’; comp. Gr. γλαύκωμα, from γλαύξ, ‘owl.’ Hence the instinctive connection between the name of the bird and the disease is quite comprehensible.