Hydrolyzes DNA under acidic conditions. Does not require divalent cations for activity. Participates in the degradation of nuclear DNA during lens cell differentiation. Endonucleolytic cleavage to nucleoside 3'-phosphates and 3'-phosphooligonucleotide end-products. Highly expressed in the eye lens and in salivary gland. Detected at lower levels in lung, prostate and lymph node. Isoform 2 is lung specific. Belongs to the DNase II family.