From theoretical considerations, the nervous system is likely to be particularly vulnerable to oxidative stress. The brain contains high concentrations of polyunsaturated fatty acids that are susceptible to lipid peroxidation, receives a disproportionately large percentage of oxygen, is relatively deficient in antioxidant systems, and contains specific regions that have high concentrations of iron. The retina is also served with a plentiful supply of oxygen, has an abundant supply of mitochondria, and has an unusually high rate of oxidative metabolism. The retinal rod outer segments are particularly vulnerable to lipid peroxidation as more than 65 % of the membrane fatty acids are polyunsaturated, which is the highest proportion found in any vertebrate tissue examined to date. The retina is also frequently exposed to intense light, which can be phototoxic. There are essentially two situations where oxidative stress may be involved in neural and retinal dysfunction: where there is a deficiency of an antioxidant and where antioxidant protection is compromised by increased oxidative stress. In both of these situations treatment with added antioxidants may be beneficial. These two aspects are considered in turn in this chapter. The chapter discusses antioxidant deficiency, decreased serum concentrations of vitamin E in the newborn and oxidative stress, intraventriculor hemorrhage (IVH), and retinopathy of prematurity (ROP). There are notes on the chronic fat malabsorptive states such as abetalipoproteinemia, retinal involvement in fat malabsorptive states, familial isolated vitamin E deficiency, and neuropathology associated with vitamin E deficiency. Observations from the functional and biochemical studies in a rat model of vitamin E deficiency are given. Oxygen-derived free radicals have been implicated in the pathogenesis of a number of neurological conditions discussed—Parkinson's disease, Tardive dyskinesia, Down syndrome, Alzheimer's disease,Motor Neuron disease, Ischemia/Reperfusion and trauma. There is mention of Neuronal ceroid lipofuscinoses (NCL) or Batten's disease.