Lysophosphatidylcholine (LPC) has been shown to be toxic to the lens in organ culture. An investigation into whether vitamin E counteracts the in vitro damaging effect of LPC on rat lenses was undertaken. A concentration higher than 10 micrograms ml-1 LPC in the culture medium is necessary to damage rat lenses, as assessed by protein content of the medium and Na+ and K+ content of the lens. Vitamin E affords its protection when present at a concentration of 10(-3) M: both the protein efflux from the lens and the lenticular cation imbalance are prevented, also if LPC concentration is 100 micrograms ml-1. This effect may be due more to the physicochemical properties of vitamin E in the stabilization of biological membranes, than to its chemical behaviour as an antioxidant.