As to vision loss, the wood alcohol in aspartame converts to formaldehyde and then formic acid, even in the retina of the eye and destroys the optic nerve. As to joint pain, aspartame hardens the synovial fluids and causes this horrible joint pain. Of course, if they are still using aspartame the drugs can interact because aspartame is a drug and not an additive as the FDA would have you believe. It says that aspartame actually makes you crave carbohydrates. It's not a diet product.
Most people gain weight on aspartame.
Also, about memory loss, aspartame is legend at causing it. H. J. Roberts, M.D., has already declared Aspartame Disease a world plague and is about to publish his 800 page medical text on this world epidemic. You can write Jane Henney of the FDA about this recent news that the Yogurt Association wants the FDA to allow sweeteners in yogurt unlabeled. Should the FDA do this which is against the law they should be immediately indicted for malfeasance. The FDA approved aspartame even though the Board of Inquiry said it hadn't been proven safe and should not be approved.