Actually, there might be something to it. Lots of in-vitro studies and several in-vivo studies including the one reported. Might be problem for people that overexpress SVCT2 transporters in the eye.
Vitamin C mediates chemical aging of lens crystallins by the Maillard reaction in a humanized mouse model
http://www.ncbi.nlm.nih.gov/pubmed/17075057Here is the full study about women and cataractas
http://www.ncbi.nlm.nih.gov/pubmed/19923367I suppose that this is contextual. For instance glutathion depletion in the eye or some other enzyme related to recycling of DHAA to AA. The risk seem small enough anyway (non significant as reported by authors) and studies are also conflicting.
Also:
Our outcome was cataract extraction instead of cataract diagnosis because of the lack of standardized eye examinations in the entire cohort and incomplete information on cataract status from medical records. We cannot, therefore, exclude the possibility of misclassification of outcome as lens opacities can exist without symptoms; this would draw the risk estimates toward no asso-ciation.
...
However, the exact dose of ascorbic acid in sup-plements was unknown.
But I agree that vitamin C proven positives by far exceed potential negatives.