One year ago we reported 432 cases of cataract extraction in which α-chymotrypsin was used to aid in zonulolysis.1We are now reporting its use in 491 additional cases performed by the same authors in the same institutions. Eighty-eight of these were performed by the resident surgeons of Wills Eye Hospital under close supervision. Our results have again been tabulated according to the questionnaire on α-chymotrypsin suggested by the Committee on Alpha-Chymotrypsin of the American Academy of Ophthalmology and Otolaryngology. The following 4 preparations of α-chymotrypsin were used: 1. Alpha Chymar (Armour Laboratories, Kankakee, Ill.) 2. Quimotrase (PEVYA Laboratories, Barcelona, Spain) 3. Zolyse (Alcon Laboratories, Fort Worth, Texas) 4. Chymexon (Schieffelin and Co., New York) We were not aware of any difference in the action of these products. We have agreed on a 1:5,000 solution because we believe this concentration assures us of the best result. We have not