The lipids of lenses from normal rats have been compared with those from cataractous and clearing lenses from rats fed triparanol. Desmosterol was about 1% of the sterols of normal lenses but amounted to approximately 10% of the sterols in lenses of triparanol-treated rats. Clearing and cataractous lenses contained about the same amount of desmosterol. On a ‘per lens’ basis, and with the exception of sphingomyelin, cataractous lenses contained less phospholipids than control lenses. Clearing lenses were intermediate and showed a tendency to return to normal values. The composition of the phospholipids showed a persistent decrease in phosphatidyl serine in the triparanol-treated animals.