Age is by far the biggest risk factor for cataract, and it is sometimes assumed that cataract is
simply an amplification of this aging process. This appears not to be the case, since the lens
changes associated with aging and cataract are distinct. Oxidation is the hallmark of age-
related nuclear (ARN) cataract. Loss of protein sulfhydryl groups, and the oxidation of
methionine residues, are progressive and increase as the cataract worsens until> 90% of
cysteine and half the methionine residues are oxidised in the most advanced form. By …