The present invention includes pharmaceutical composition comprising (2R,2R′)-3,3′-disulfanediyl bis(2-acetamidopropanamide)(diNACA) or D3-N-acetyl cysteine amide, or a physiologically acceptable salt thereof, having a deuterium enrichment above the natural abundance of deuterium, and derivatives or solids thereof, and methods of using diNACA to treat eye diseases and other diseases associated with oxidative damage including, e.g., antivenom, beta-thallassemia, cataract, chronic obstructive pulmonary disease, macular degeneration, contrast-induced nephropathy, asthma, lung contusion, methamphetamine-induced oxidative stress, multiple sclerosis, Parkinson's disease, platelet apoptosis, Tardive dyskinesia, Alzheimer disease, HIV-1-associated dementia, mitochondrial diseases, myocardial myopathy, neurodegenerative diseases, pulmonary fibrosis, skin pigmentation, skin in need of rejuventation, antimicrobial infection, Friedreich's ataxia.