(A) Metabolites from young and old lens were separated into two different groups in Scores Plot by PCA. (B) Top enriched pathways from the significantly changed metabolites. (C) Top decreased metabolites in the old lens. 5-MT-Adenosine, 5’- Methylthioadenosine; 4-GDBA, 4-Guanidinobutanoate; DMPD, N,N-Dimethyl-1,4-Phenylenediamine. (D) Top increased metabolites in the old lens. 1-methylNAA, 1-Methylnicotinamide; CDP, Cytidine 5’- Diphosphocholine. Data are fold change of ion intensity of the old vs the young. N=4.