The natural history of neurocognitive impairment in human immunodeficiency virus (HIV)-infected individuals remains poorly understood. While the advent of highly active antiretroviral therapy (HAART) has led to a decreased incidence of the most severe form of HIV associated neurocognitive disorders (HAND), HIV-associated dementia, it does not appear to have impacted overall prevalence of HAND. Existing evidence suggests that the central nervous system (CNS) could be an important reservoir for HIV regardless of cumulative time on treatment. This 8 year multi-institute screening protocol will identify approximately 200 HIV-infected individuals and 100 healthy volunteers for enrollment in multiple HAND studies at the National Institutes of Health (NIH). Subjects will undergo a one-time screening and evaluation assessment, which will include neuropsychological testing, optical coherence tomography (OCT) and brain magnetic resonance imaging (MRI) and may include a more detailed ophthalmic evaluation.